Alkyl indene compound as well as modular alkyl editing synthesis method and application thereof

Abstract

The invention discloses an alkyl indene compound as well as a modular alkyl editing synthesis method and application thereof, indene and alcohol are taken as raw materials, under an alkaline condition, tridentate Mn is taken as a catalyst, and under a heating condition, modular alkyl editing synthesis is performed through a hydrogen borrowing strategy to obtain a mono-alkyl indene compound or a bis / polyalkyl indene compound. The synthesized mono-alkyl indene compound and a substituted boric acid (or alkyne or amide) derivative are further converted to realize selective functional group editing at the site 2 of the mono-alkyl indene compound, so that the indene compound with diversified functional groups at the site 2 is obtained; the method can also be applied to rhodium catalyst synthesis. The invention develops a more efficient selective single or double / polyalkyl editing method of the indene compounds, provides more indene compounds containing monoalkyl substitution, double alkyl substitution and polyalkyl substitution, and has wider functional group compatibility, including amino, hydroxyl, ether, alkenyl, halogen and heterocyclic active groups.

Description

Technical Field

[0001] The present invention belongs to the field of chemical synthesis, and particularly relates to a class of alkyl indene compounds, a modular alkyl editing synthesis method thereof, and applications thereof. Background Art

[0002] Indene compounds are widely used in drugs (J. Med. Chem. 1998, 41, 5177 - 5187; J. Med. Chem. 2002, 45, 4212 - 4221), functional materials (Progress in Polymer Science, 2012, 37, 1192 - 1264; J. Am. Chem. Soc. 2013, 135, 15326 - 15329; Angew. Chem. Int. Ed. 2016, 55, 14522 - 14545) and ligands of their catalysts (Angew. Chem. Int. Ed. 1999, 38, 2064 - 2066; J. Am. Chem. Soc. 2013, 135, 8830 - 8833; Angew. Chem. Int. Ed. 2017, 56, 2862 - 2879) due to their unique aromaticity and all - carbon skeleton structure. Therefore, finding a simple and efficient method to synthesize such compounds is a current research hotspot. Traditionally, the alkylation transformation of indene often requires haloalkanes or aldehydes and ketones as alkyl sources (Polyhedron, 2018, 144, 176 - 186; Inorg. Chem. 2021, 60, 9833 - 9847; KR20200069042A); however, this method is limited by atom and step economy. Alcohols, as a green, economic and sustainable alkylating reagent, have attracted great interest from chemists. For example, using alcohol as an alkylating reagent and through a C - H bond activation strategy, Yi and his collaborators developed a ruthenium - catalyzed system to achieve the alkylation at the 2 - position of indene (Science. 2011, 333, 1613 - 1616); recently, through a borrowing - hydrogen strategy, the Tu research group developed a selective mono - alkylation reaction of indene and alcohol catalyzed by noble metal iridium (Angew. Chem. Int. Ed. 2022, e202206446). However, the above methods not only have expensive catalysts and limited substrate compatibility, but also it is difficult to achieve selective modular alkyl editing at multiple sites of indene. Not long ago, our research group made a certain breakthrough and developed a cheap metal manganese - catalyzed system to achieve 3 - alkyl and 1,3 - dialkyl modifications of indene (CN202410290923.9; ACS Catal. 2024, 14, 18032 - 18044). However, in the dialkylation process of indene, this catalytic system requires an excessive amount of alcohol as a substrate; in addition, this method has low compatibility with the functional groups at the 2 - position of indene, which to a certain extent limits its practical application. Therefore, there is an urgent need to develop a more efficient method for selective modular alkyl editing at multiple sites of indene to construct a more abundant indene compounds with alkyl substitutions and their applications. Summary of the Invention

[0003] The object of the present invention is to overcome the drawbacks existing in the prior art, and provides an alkyl indene compound, a modular alkyl editing synthesis method and application thereof. This method can efficiently synthesize mono-alkyl substituted, di-alkyl substituted and multi-alkyl substituted indene compounds, and significantly improves the synthesis efficiency of such compounds.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] An alkyl indene compound, the general structural formula thereof is as follows:

[0006]

[0007] Among them, R 1 represents one or two substituents on the connected benzene ring, and each R 1 substituent is independently selected from hydrogen, halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, aryl, nitro, cyano or ester group.

[0008] R 2 is selected from hydrogen, aralkyl, heteroaralkyl, C 1 -C 12 alkyl or functional group-containing alkyl.

[0009] R 3 is selected from hydrogen, halogen, hydroxyl, amino, C 1 -C 6 alkyl, alkenyl, alkynyl or aryl.

[0010] R 4 is selected from aralkyl, heteroaralkyl, C 1 -C 12 alkyl or functional group-containing alkyl; when R 2 is not hydrogen, R 4 is equivalent to R 2 .

[0011] Among the above R 2 and R 4 : for the aralkyl, the substituents on the aryl are hydrogen, fluorine, chlorine, bromine, iodine, methyl, trifluoromethyl, methoxy, methylthio or alkenyl, and the alkyl is methylene, ethylene or propylene; for the heteroaralkyl, the heteroaryl is pyridine, furan or thiophene, and the alkyl is methylene, ethylene or propylene; for the C 2 -C 12 alkyl is a C 2 -C 12 linear alkyl or branched alkyl; the functional group-containing alkyl is alkenylalkyl, methoxyalkyl, hydroxyalkyl, aminoalkyl or alkenylalkyl.

[0012] Preferably, R 1 is hydrogen, fluorine, chlorine, bromine, C 1 -C 6 alkyl, methoxy or aryl.

[0013] More preferably, R 1 is hydrogen, fluorine, chlorine, bromine, methyl or phenyl.

[0014] More preferably, R 2 is hydrogen, butyl, pentyl, hexyl, isobutyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 4-ene-hexyl, benzyl, with substituents on the benzene ring (the substituents are methyl, methoxy, fluorine, chlorine, bromine, iodine or trifluoromethyl), 2-pyridylmethyl or 2-furanylmethyl.

[0015] Preferably, R 3 is hydrogen, bromine, methyl, hydroxyl, amino, alkenyl, alkynyl or aryl; the hydroxyl is a hydroxyl protected by triisopropylsilyl; the amino is an arylcarboxamide (the aryl contains hydrogen, methyl, methoxy, fluorine, chlorine or trifluoromethyl substituents); the alkenyl is arylvinyl, C 4 -C 10 alkenyl; the alkynyl is arylethynyl (the aryl contains hydrogen, methyl, methoxy, fluorine, chlorine or trifluoromethyl substituents), C 4 -C 10 alkynyl; the aryl is an aryl containing hydrogen, methyl, methoxy, fluorine, chlorine or trifluoromethyl substituents.

[0016] More preferably, R 3 is bromine, methyl, styryl, phenyl, 2,4,6-trimethylphenyl, styryl or 4-phenylbutynyl.

[0017] More preferably, R 4 is butyl, pentyl, hexyl, isobutyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 4-ene-hexyl, benzyl, with substituents on the benzene ring (the substituents are methyl, methoxy, fluorine, chlorine, bromine, iodine or trifluoromethyl), 2-pyridylmethyl or 2-furanylmethyl; when R 2 is not hydrogen, R 4 is equivalent to R 2 .

[0018] Furthermore, the alkyl indene compounds preferably include the following compounds:

[0019] (1) 2-bromo-3-benzyl-1H-indene

[0020] (2) 2-bromo-3-(4-methylbenzyl)-1H-indene

[0021] (3) 2-Phenyl-3-benzyl-1H-indene

[0022] (4) 1,3-Dipentyl-2-bromoindene

[0023] (5) 1,3-Bis(4-iodobenzyl)-2-methylindene

[0024] (6) 2-Mesityl-3-(4-methylbenzyl)-1H-indene

[0025] (7) (E)-3-(4-Methylbenzyl)-2-styryl-1H-indene

[0026] (8) 3-(4-Methylbenzyl)-2-(4-phenylbut-1-yne)-1H-indene

[0027] (9) 4,4,5,5-Tetramethyl-2-(3-(4-methylphenyl)-1H-indene-2-yl)-1,3,2-dioxaborolane

[0028] (10) 4-Methyl-N-(3-(4-methylphenyl)-1H-indene-2-yl)benzamide.

[0029] The modular alkyl editing synthesis method of the alkyl indene compounds uses indene (Formula 1) and alcohol (Formula 2) as raw materials. Under alkaline conditions, with a tridentate Mn catalyst, through a borrowing hydrogen strategy under heating conditions, modular alkyl editing synthesis is carried out to obtain mono-alkyl indene compounds (Formula 3) or bis / multi-alkyl indene compounds (Formula 4). The specific reaction formula is as follows:

[0030]

[0031] Where the substituent R 1 , R 2 , R 3 and R 4 are as described above.

[0032] The above synthesis method is carried out in an organic solvent, and the organic solvent is one or a mixture of toluene, 1,4-dioxane, tetrahydrofuran, 1,2-dichloroethane, and n-hexane.

[0033] The catalyst is a tridentate Mn catalyst (PNP-Mn), and the structural formula is as follows:

[0034]

[0035] Wherein, R 5 is taken from phenyl, isopropyl or cyclohexyl.

[0036] The basic condition uses an inorganic base, and the inorganic base is selected from one or more of sodium hydride, potassium tert-butoxide, sodium tert-butoxide, potassium hydroxide, sodium hydroxide, lithium hydroxide, potassium phosphate, cesium carbonate, potassium carbonate or sodium carbonate.

[0037] The purification and separation of the product can be carried out by extraction, thin-layer chromatography or column chromatography; column chromatography is preferably used, and the developing solvent used is a non-polar solvent or a mixture of a polar solvent and a non-polar solvent. Depending on the product, the developing solvent is preferably petroleum ether, petroleum ether-ethyl acetate or dichloromethane-methanol.

[0038] More specifically, the synthesis method of the mono-alkyl indene compound (Formula 3) is as follows: Mix 0.3 molar parts of alcohol, 0.3 - 0.6 molar parts of indene (Formula 1), 0.003 - 0.015 molar parts of PNP-Mn, 0.03 - 0.3 molar parts of base and an organic solvent, stir at 80 - 140 °C for 1 - 24 h. After the reaction is completed, the organic solvent is removed under reduced pressure, and the residue is separated by column chromatography with a n-hexane eluent to obtain the mono-alkyl indene compound.

[0039] More specifically, the synthesis method of the bis-alkyl indene compound (Formula 4) is as follows: When the 2-position of indene (Formula 1) does not contain a methyl group, mix 0.6 - 1.5 molar parts of alcohol, 0.3 molar parts of indene (Formula 1), 0.003 - 0.015 molar parts of PNP-Mn, 0.03 - 0.3 molar parts of base and an organic solvent, stir at 100 - 140 °C for 1 - 24 h. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography with a n-hexane eluent to obtain the bis-alkyl indene compound.

[0040] More specifically, the synthesis method of the multi-alkyl indene compound (Formula 4) is as follows: When the 2-position of indene (Formula 1) contains a methyl group, mix 0.6 - 1.5 molar parts of alcohol, 0.3 molar parts of indene (Formula 1), 0.003 - 0.015 molar parts of PNP-Mn, 0.03 - 0.3 molar parts of base and an organic solvent, stir at 100 - 140 °C for 1 - 24 h. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography with a n-hexane eluent to obtain the multi-alkyl indene compound.

[0041] In the present invention, the main difference between the mono-alkyl modular editing and the bis / multi-alkyl modular editing of indene is the molar ratio of indene to alcohol in the reactants, and the main difference between the bis-alkyl and multi-alkyl modular editing of indene is whether the 2-position of the indene substrate (Formula 1) contains a methyl group.

[0042] The alkyl indene compounds prepared by the modular alkyl editing synthesis method of the present invention have good potential value and can be further subjected to complex transformation and application. Specific examples are as follows:

[0043] First: The single-alkyl indene compound (Formula 5) of the present invention can be further converted with a substituted boric acid (or alkyne or amide) derivative to achieve selective functional group editing at the 2-position of the single-alkyl indene compound, obtaining indene compounds with more diverse functional groups at the 2-position. The reaction formula is as follows:

[0044]

[0045] In the above reaction formula, R is taken from aryl, alkenyl or substituted alkyl, preferably phenyl, mesityl, styryl or 2-phenylethyl; R 6 is taken from aryl, 2-phenylethenyl, arylacetylene, alkylacetylene or arylformamide, preferably mesityl, styryl, phenylethynyl or benzamide.

[0046] Specifically, for the further selective functional group editing at the 2-position of the single-alkyl indene compound, 0.2 - 0.3 molar parts of the single-alkyl indene compound (Formula 5), 0.3 - 0.45 molar parts of the substituted boric acid (or alkyne or amide) derivative, 0.002 - 0.015 molar parts of the catalyst Pd(PPh 3 ) 4 (or Pd(PPh 3 ) 2 Cl 2 or CuI), 0.3 - 0.9 molar parts of the base and 1 - 2 mL of the solvent are placed in a sealed tube; then it is sealed and taken out, and the reaction mixture is stirred at 60 - 120 °C for 1 - 24 h. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain the product of selective functional group editing at the 2-position of the monoalkyl indene.

[0047] Second: The single-alkyl indene compound of the present invention can be applied to the synthesis of rhodium catalysts. Specifically, 0.2 - 0.3 molar parts of the single-alkyl indene compound (Formula 7), 0.1 - 0.2 molar parts of [Rh(COD) 2 Cl] 2 , 0.3 - 0.4 molar parts of KO t Bu and THF (4 mL) are placed in a sealed tube, and the mixture is reacted at room temperature for 10 - 24 h. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain the precursor of the 3-Rh catalyst of the formula.

[0048]

[0049] The principle of the present invention is as follows:

[0050] (1) Through the hydrogen borrowing strategy, PNP-Mn catalyzes the dehydrogenation of alcohol to generate aldehyde Int1 and metal hydride PNP-Mn-H intermediate. Then, under alkaline conditions, indene undergoes dehydration condensation with aldehyde to form unsaturated carbon-carbon double bond Int2, which is subsequently reduced by metal hydride to generate monoalkylated product 3a;

[0051]

[0052] (2) If the amount of alcohol is twice or more that of indene, the monoalkylated product 3a can undergo alkylation reaction again to obtain dialkylated product 4a; if indene has a methyl group at the 2nd position and the amount of alcohol is twice or more that of indene, a polyalkylated product is obtained.

[0053]

[0054] (3) When the 2nd position of alkyl-substituted indene contains bromine, it can directly achieve further functional group transformation of alkyl indene through Suzuki coupling or Buchwald–Hartwig cross-coupling reaction.

[0055] The present invention has the following advantages and effects compared with the prior art:

[0056] (1) The present invention develops a more efficient method for selective mono- or di- / poly-alkylation editing of indene compounds, providing more indene compounds containing monoalkyl substitution, dialkyl substitution, and polyalkyl substitution.

[0057] (2) The present invention has a wider functional group compatibility, including amino, hydroxyl, ether, alkenyl, halogen, and heterocyclic active groups.

[0058] (3) The present invention further explores the transformation, rhodium-catalyzed synthesis, and application of mono-alkyl indene compounds, expanding the application scope of this indene compound. Detailed implementation manners

[0059] To facilitate the understanding of the present invention, the present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention. However, the present invention is not limited in any form. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, the present invention can be subject to several modifications and improvements, which all fall within the protection scope of the present invention.

[0060] Example 1: Synthesis of manganese catalyst (PNP-Mn)

[0061] Synthesis of PNP-Mn-1 catalyst (see Angew. Chem. Int. Ed. 2019, 58, 775-779), the reaction formula is as follows:

[0062]

[0063] Specifically, it is carried out according to the following steps:

[0064] Add the phosphine ligand L1 and the corresponding Mn(CO) 5 Br into toluene solvent in a molar dosage ratio of 1:(1.0 - 1.5). After reacting at 110 °C for 24 h, cool it to room temperature; then wash with DCM, dry the filtrate, spin-dry it to obtain a yellow solid, namely PNP-Mn-1.

[0065] (I) Mono-alkyl indene compounds and examples of their synthesis

[0066] Example 2: Synthesis of 3-(4-methylbenzyl)-1H-indene (3a):

[0067]

[0068] The specific experimental operation is as follows: In a glove box, add 4-methylbenzyl alcohol (0.3 molar portion), indene (0.3 molar portion), PNP-Mn-1 (0.003 molar portion), KOH (0.03 molar portion) and n-hexane (1 mL) successively to a dry pressure-resistant sealed tube equipped with magnetic stirring. Then seal it and take it out. Stir the reaction mixture at 100 °C for 2 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is eluted with n-hexane and separated by column chromatography to obtain the target product of formula 3a (56 mg, colorless oil, 85% yield).

[0069] 3-(4-methylbenzyl)-1H-indene (3a): 1 H NMR (400 MHz, Chloroform-d) δ 7.50 (d, J = 7.3 Hz, 1H), 7.34 (s, 1H), 7.28 (d, J = 7.4 Hz, 1H), 7.22 (d, J = 7.8 Hz, 3H), 7.15 (d, J = 7.7 Hz, 2H), 6.17 (s, 1H), 3.91 (s, 2H), 3.39 (s, 2H), 2.37 (s, 3H). 13 C NMR (100 MHz, Chloroform-d) δ 145.3, 144.7, 143.8, 136.4, 135.7, 123.0, 129.2, 128.9, 126.1, 124.7, 123.9, 119.5, 37.8, 34.1, 21.2.

[0070] Example 3: Synthesis of 3-(4-bromobenzyl)-1H-indene (3b):

[0071]

[0072] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 4-bromobenzyl alcohol (0.3 mol portion), indene (0.45 mol portion), PNP-Mn-1 (0.015 mol portion), KOH (0.3 mol portion) and n-hexane (0.5 mL) were added in sequence. Then it was sealed and taken out. The reaction mixture was stirred at 80 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography to obtain the target product of formula 3b (63.9 mg, white solid, 75%).

[0073] 3-(4-bromobenzyl)-1H-indene (3b): 1 H NMR (400 MHz, Chloroform-d) δ 7.49 (d, J = 7.3 Hz, 1H), 7.44 (d, J = 8.4 Hz, 2H), 7.28 (d, J = 3.8 Hz, 2H), 7.25 - 7.21 (m, 1H), 7.18 (d, J = 8.4 Hz, 2H), 6.16 (s, 1H), 3.88 (s, 2H), 3.38 (d, J = 2.1 Hz, 2H). 13 C NMR (100 MHz, Chloroform-d) δ 144.9, 144.6, 143.0, 138.5, 131.6, 130.8, 130.4, 126.2, 124.90, 124.0, 120.1, 119.4, 37.9, 34.0.

[0074] Example 4: Synthesis of 3-butyl-1H-indene (3c):

[0075]

[0076] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, n-butanol (0.3 mol portion), indene (0.6 mol portion), PNP-Mn-1 (0.003 mol portion), KOH (0.09 mol portion) and n-hexane (1 mL) were added in sequence. Then it was sealed and taken out. The reaction mixture was stirred at 100 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography to obtain the target product of formula 3c (45.0 mg, colorless oil, 87%).

[0077] 3-butyl-1H-indene (3c): 11H NMR (400 MHz, Chloroform-d) δ 7.48 (d, J = 7.3 Hz, 1H), 7.40 (d, J = 7.5 Hz, 1H), 7.32 (t, J = 7.4 Hz, 1H), 7.22 (dd, J = 8.0, 6.7 Hz, 1H), 6.22 (s, 1H), 3.35 (s, 2H), 2.62 - 2.52 (m, 2H), 1.75 - 1.64 (m, 2H), 1.46 (q, J = 7.4 Hz, 2H), 0.99 (t, J = 7.3 Hz, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 145.8, 144.8, 144.7, 127.7, 126.1, 124.5, 123.8, 119.1, 37.8, 30.3, 27.6, 22.9, 14.2.

[0078] Example 5: Synthesis of 3-cyclobutylmethyl-1H-indene (3d):

[0079]

[0080] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, sequentially add cyclobutanemethanol (0.3 mol portion), indene (0.3 mol portion), PNP-Mn-1 (0.015 mol portion), KOH (0.09 mol portion) and n-hexane (1 mL). Then seal and take out. Stir the reaction mixture at 100 °C for 10 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is separated by column chromatography to obtain the target product of formula 3d (46.6 mg, colorless oil, 86%).

[0081] 3-cyclobutylmethyl-1H-indene (3d): 1 1H NMR (400 MHz, Chloroform-d) δ 7.48 (d, J = 7.3 Hz, 1H), 7.38 (d, J = 7.4 Hz, 1H), 7.32 (t, J = 7.3 Hz, 1H), 7.23 (t, J = 7.4 Hz, 1H), 6.18 (s, 1H), 3.34 (t, J = 2.4 Hz, 2H), 2.80 - 2.71 (m, 1H), 2.71 - 2.64 (m, 2H), 2.16 (dtd, J = 9.9, 7.4, 4.5 Hz, 2H), 1.98 - 1.86 (m, 2H), 1.81 - 1.74 (m, 2H). 1313C NMR (100 MHz, Chloroform-d) δ 145.9, 144.6, 143.2, 128.0, 126.1, 124.5, 123.8, 119.0, 37.9, 35.1, 34.5, 28.7, 18.6. APCI-HRMS: m / z calculated for C14H17 [M+H] + : 185.1325; found: 185.1324.

[0082] Example 6: Synthesis of 2-(1-indan-3-yl)ethyl)thiophene (3e):

[0083]

[0084] The specific experimental procedure is as follows: In a glove box, 2-thiophene ethanol (0.3 mol portion), indene (0.3 mol portion), PNP-Mn-1 (0.003 mol portion), KOH (0.1 mol portion) and n-hexane (1 mL) were successively added to a dry pressure-resistant sealed tube equipped with magnetic stirring. Then it was sealed and taken out. The reaction mixture was stirred at 100 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography to obtain the target product of formula 3e (47.4 mg, colorless oil, 70%).

[0085] 2-(1-indan-3-yl)ethyl)thiophene (3e): 1 1H NMR (400 MHz, Chloroform-d) δ 7.50 (d, J = 7.3 Hz, 1H), 7.41 (d, J = 7.4 Hz, 1H), 7.34 (t, J = 8.4, 7.5, 1H), 7.26 - 7.21 (m, 1H), 7.16 (dd, J = 5.1, 1.4 Hz, 1H), 6.96 (dd, J = 5.1, 3.4 Hz, 1H), 6.88 (dd, J = 3.5, 1.1 Hz, 1H), 6.28 (s, 1H), 3.37 (q, J = 2.3 Hz, 2H), 3.32 - 3.21 (m, 2H), 2.99 - 2.94 (m, 2H). 13 13C NMR (100 MHz, Chloroform-d) δ 145.3, 145.0, 144.5, 143.4, 128.5, 126.9, 126.2, 124.8, 124.4, 123.9, 123.2, 119.0, 37.9, 30.2, 28.6.

[0086] Example 7: Synthesis of 3-(4-methoxybutyl)-indene (3f):

[0087]

[0088] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 4-methoxybutanol (0.3 mol equiv), indene (0.45 mol equiv), PNP-Mn-1 (0.009), KOH (0.3 mmol), and n-hexane (1 mL) were added successively. Then, the tube was sealed and taken out. The reaction mixture was stirred at 100 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography to obtain the target product of formula 3f (50.9 mg, pale yellow oil, 70%).

[0089] 3-(4-Methoxybutyl)-indene (3f): 1 H NMR (400 MHz, Chloroform-d) δ 7.46 (d, J = 8, 1H), 7.37 (d, J = 8, 1H), 7.33 - 7.27 (m, 1H), 7.22 - 7.18 (m, 1H), 6.22 (s, 1H), 3.43 (t, J = 6.3 Hz, 2H), 3.35 - 3.35 (m, 5H), 2.61 - 2.56 (m, 2H), 1.81 - 1.66 (m, 4H). 13 C NMR (100 MHz, Chloroform-d) δ 145.6, 144.7, 144.4, 127.99, 126.1, 124.6, 123.9, 119.1, 72.9, 58.7, 37.8, 29.7, 27.7, 24.7. ACPI-HRMS: m / z calculated for C15H18O [M + H] + : 203.1430; found: 203.1435.

[0090] Example 8: Synthesis of 6-(1H-inden-3-yl)-hexan-1-ol (3g):

[0091]

[0092] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 1,6-hexanediol (0.3 mol equiv), indene (0.3 mol equiv), PNP-Mn-1 (0.003 mol equiv), KOH (0.09 mol equiv), and n-hexane (0.5 mL) were added successively. Then, the tube was sealed and taken out. The reaction mixture was stirred at 140 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography to obtain the target product of formula 3g (46.0 mg, pale yellow oil, 71%).

[0093] 6-(1H-inden-3-yl)-hexan-1-ol (3g): 11H NMR (400 MHz, Chloroform-d) δ 7.46 (d, J = 7.3 Hz, 1H), 7.37 (d, J = 7.5 Hz, 1H), 7.30 (t, J = 7.2 Hz, 1H), 7.22 - 7.18 (m, 1H), 6.20 (s, 1H), 3.65 (t, J = 6.6 Hz, 2H), 3.33 (q, J = 2.3 Hz, 2H), 2.60 - 2.52 (m, 2H), 1.72 (t, J = 7.5 Hz, 2H), 1.63 - 1.54 (m, 2H), 1.46 - 1.43 (m, 4H), 1.32 (s, 1H). 13 13C NMR (100 MHz, Chloroform-d) δ 145.7, 144.7, 127.8, 126.1, 124.6, 123.9, 119.1, 63.2, 37.8, 32.9, 29.6, 28.1, 27.8, 25.8.

[0094] Example 9: Synthesis of 3-(1H-inden-3-yl)-1-phenylpropan-1-amine (3h):

[0095]

[0096] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 3-amino-3-phenylpropan-1-ol (0.3 mol portion), indene (0.45 mol portion), PNP-Mn-1 (0.003 mol portion), KOH (0.3 mol portion) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 80 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography to obtain the target product of formula 3h (62.0 mg, pale yellow oil, 83%).

[0097] 3-(1H-inden-3-yl)-1-phenylpropan-1-amine (3h): 1 1H NMR (400 MHz, Chloroform-d) δ 7.48 (d, J = 7.3 Hz, 1H), 7.39 (d, J = 4.4 Hz, 4H), 7.34 - 7.27 (m, 3H), 7.22 (td, J = 6.7, 2.3 Hz, 1H), 6.24 (s, 1H), 4.04 (t, J = 6.8 Hz, 1H), 3.35 (s, 2H), 2.68 - 2.58 (m, 1H), 2.58 - 2.46 (m, 1H), 2.12 (q, J = 7.8 Hz, 2H), 1.82 (s, 2H). 1313C NMR (100 MHz, Chloroform-d) δ 146.3, 145.4, 144.6, 144.0, 128.7, 127.9, 127.2, 126.6, 126.1, 124.7, 123.8, 119.0, 37.8, 37.7, 24.8.

[0098] Example 10: Synthesis of 3-benzyl-7-bromo-1H-indene (3i):

[0099]

[0100] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, add benzyl alcohol (0.3 molar parts), 7-bromoindene (0.3 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.03 molar parts) and n-hexane (0.5 mL) in sequence. Then seal and take out. Stir the reaction mixture at 100 °C for 18 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is separated by column chromatography to obtain the target product of formula 3i (67.9 mg, colorless oil, 79%).

[0101] 3-benzyl-7-bromo-1H-indene: (3i)

[0102] 1 1H NMR (400 MHz, Chloroform-d) δ 7.33 (dd, J = 11.2, 7.5 Hz, 3H), 7.30 - 7.27 (m, 2H), 7.27 - 7.21 (m, 2H), 7.14 (t, J = 7.7 Hz, 1H), 6.23 (s, 1H), 3.90 (s, 2H), 3.36 (d, J = 2.1 Hz, 2H). 13 13C NMR (100 MHz, Chloroform-d) δ 146.8, 144.7, 143.6, 139.0 130.7, 129.0, 128.6, 128.2, 127.9, 126.4, 119.0, 118.59, 39.5, 34.7. ACPI-HRMS: m / z calculated for C16H14Br [M + H] + : 285.0273, 287.0253; found: 285.0272, 287.0252.

[0103] Example 11: Synthesis of 2-methyl-3-benzyl-1H-indene (3j):

[0104]

[0105] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 molar parts), benzyl alcohol (0.3 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.1 mmol) and n-hexane (1 mL) were successively added. Then it was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 3j (52.8 mg, colorless oil, 80% yield).

[0106] 2-Methyl-3-benzyl-1H-indene (3j): 1 H NMR (400 MHz, Chloroform-d) δ 7.36 (d, J = 7.2 Hz, 1H), 7.26 - 7.21 (m, 4H), 7.17 - 7.13 (m, 2H), 7.11 - 7.05 (m, 2H), 3.88 (s, 2H), 3.36 (s, 2H), 2.14 (s, 3H). 13 C NMR (100 MHz, Chloroform-d) δ 146.7, 142.6, 140.7, 134.0, 135.5, 128.51, 128.4, 126.2, 126.0, 123.8, 123.2, 118.9, 42.8, 31.4, 14.4. ACPI-HRMS: m / z calculated for C17H17[M + H] + : 221.1325; found: 221.1323.

[0107] Example 12: Synthesis of 2-bromo-3-benzyl-1H-indene (3k):

[0108]

[0109] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 2-bromo-1H-indene (0.3 molar parts), benzyl alcohol (0.3 molar parts), PNP-Mn-1 (0.015 molar parts), KOH (0.1 mmol) and n-hexane (1 mL) were successively added. Then it was sealed and taken out. The reaction mixture was stirred at 100 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 3k (60 mg, colorless oil, 70% yield).

[0110] 2-Bromo-3-benzyl-1H-indene (3k): 11H NMR (400 MHz, Chloroform-d) δ 7.41 (d, J = 6.8 Hz, 1H), 7.38 - 7.27 (m, 4H), 7.26 - 7.16 (m, 4H), 4.03 (s, 2H), 3.72 (s, 2H). 13 13C NMR (100 MHz, Chloroform-d) δ 143.8, 142.3, 141.0, 138.2, 128.6, 126.6, 126.5, 125.0, 123.3, 122.9, 119.6, 44.8, 33.1. ACPI-HRMS: m / z calculated for C16H13Br [M+H] + : 285.0273, 287.0253; found: 285.0274, 287.0253.

[0111] Example 13: Synthesis of 2-bromo-3-(4-methylbenzyl)-1H-indene (3l):

[0112]

[0113] The specific experimental procedure is as follows: In a glove box, to a dry pressure-resistant sealed tube equipped with magnetic stirring, 2-bromo-1H-indene (0.45 molar parts), 4-methylbenzyl alcohol (0.3 molar parts), PNP-Mn-1 (0.015 molar parts), KOH (0.1 mmol) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 100 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 3l (60 mg, colorless oil, 70% yield).

[0114] 2-bromo-3-(4-methylbenzyl)-1H-indene (3l): 1 1H NMR (400 MHz, Chloroform-d) δ 7.37 (d, J = 7.1 Hz, 1H), 7.23 - 7.06 (m, 7H), 3.95 (s, 2H), 3.68 (s, 2H), 2.31 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 143.9, 142.4, 141.2, 135.9, 135.1, 129.3, 128.5, 126.6, 124.9, 123.3, 122.6, 119.6, 44.8, 32.6, 21.2.

[0115] Example 14: Synthesis of 2-phenyl-3-benzyl-1H-indene (3m):

[0116]

[0117] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, 2-phenyl-1H-indene (0.3 molar parts), benzyl alcohol (0.3 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.1 molar parts) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 80 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product shown in Formula 3m (60 mg, colorless oil, 71% yield).

[0118] 2-Phenyl-3-benzyl-1H-indene (3m): 1 H NMR (400 MHz, Chloroform-d) δ 7.60 - 7.55 (m, 1H), 7.54 - 7.49 (m, 2H), 7.44 (t, J = 7.5 Hz, 2H), 7.38 - 7.30 (m, 5H), 7.30 - 7.24 (m, 3H), 7.23 - 7.20 (m, 1H), 4.22 (s, 2H), 3.95 (s, 2H). 13 C NMR (100 MHz, Chloroform-d) δ 146.6, 143.0, 142.7, 139.6, 137.2, 136.6, 128.7, 128.7, 128.4, 128.1, 127.3, 126.5, 126.2, 124.9, 123.5, 120.3, 41.5, 32.3. ACPI-HRMS: m / z calculated for C22H19[M + H] + : 283.1481; found: 283.1480.

[0119] Example 15: Synthesis of triisopropyl(3-phenyl-1H-indene-2-yl)silane (3n):

[0120]

[0121] The specific experimental operations are as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, ((1H-indene)-2-yl)triisopropylsilane (0.45 molar parts), n-pentanol (0.3 molar parts), PNP-Mn-1 (0.01 molar parts), KOH (0.3 molar parts) and n-hexane (0.5 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 120 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product shown in Formula 3n (75.0 mg, colorless oil, 70% yield).

[0122] Triisopropyl(3-phenyl-1H-inden-2-yl)silane (3n): 1 H NMR (400 MHz, Chloroform-d) δ 7.24 (dd, J=10.6, 6.8 Hz, 2H), 7.16 (d, J=7.3 Hz, 1H), 7.04 (t, J=7.4 Hz, 1H), 3.30 (s, 2H), 2.47 (t, J=7.7 Hz, 2H), 1.58 (dd, J=10.5, 4.9 Hz, 2H), 1.42 - 1.33 (m, 4H), 1.31 - 1.23 (m, 3H), 1.15 (d, J=7.0 Hz, 18H), 0.94 - 0.88 (m, 3H). 13 C NMR (100 MHz, Chloroform-d) δ 155.2, 146.4, 136.5, 126.5, 123.0, 122.4, 120.0, 117.6, 38.7, 32.3, 28.0, 23.6, 22.7, 18.1, 14.2, 13.0.

[0123] Example 16: Synthesis of 2-methyl-3-benzyl-7-phenyl-1H-indene (3o):

[0124]

[0125] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methyl-7-phenyl-1H-indene (0.3 molar portion), benzyl alcohol (0.3 molar portion), PNP-Mn-1 (0.003 molar portion), KOH (0.1 mmol) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 120 °C for 1 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography with n-hexane eluent to obtain the target product shown in formula 3o (71 mg, light yellow oil, 80% yield).

[0126] 2-methyl-3-benzyl-7-phenyl-1H-indene (3o): 1 H NMR (400 MHz, Chloroform-d) δ 7.66 (d, J=7.1 Hz, 2H), 7.56 (t, J=7.5 Hz, 2H), 7.47 (t, J=7.4 Hz, 1H), 7.41 - 7.34 (m, 5H), 7.34 - 7.22 (m, 3H), 4.05 (s, 2H), 3.58 (s, 2H), 2.26 (s, 3H). 1313C NMR (100 MHz, Chloroform-d) δ 147.2, 141.5, 140.6, 140.1, 134.0, 135.5, 128.7, 128.6, 128.5, 127.2, 127.0, 126.1, 124.6, 118.2, 42.9, 31.5, 14.4. APCI-HRMS: m / z calculated for C23H21 [M+H] + : 297.1638; found: 297.1636.

[0127] (II) Dialkylindenes and Their Synthesis

[0128] Example 17: Synthesis of 1,3-bis(4-methylbenzyl)indene (4a):

[0129]

[0130] The specific experimental procedure is as follows: In a glove box, to a dry pressure-resistant sealed tube equipped with magnetic stirring, indene (0.3 mol equiv), 4-methylbenzyl alcohol (0.6 mol equiv), PNP-Mn-1 (0.003 mol equiv), KOH (0.03 mmol), and n-hexane (1 mL) were added successively. Then the tube was sealed and taken out. The reaction mixture was stirred at 100 °C for 18 h. After completion of the reaction, the solvent was removed under reduced pressure. The residue was separated by column chromatography using n-hexane as the eluent to obtain the target product of formula 4a (84 mg, colorless oil, 95% yield).

[0131] 1,3-bis(4-methylbenzyl)indene (4a): 1 1H NMR (400 MHz, Chloroform-d) δ 7.36 - 7.31 (m, 1H), 7.30 - 7.25 (m, 2H), 7.25 - 7.12 (m, 9H), 6.18 (s, 1H), 3.89 (s, 2H), 3.78 - 3.73 (t, J = 8 Hz, 1H), 3.13 (dd, J = 13.5, 6.8 Hz, 1H), 2.81 (dd, J = 13.5, 8.6 Hz, 1H), 2.43 (s, 3H), 2.39 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 148.1, 144.8, 142.5, 137.4, 136.2, 135.7, 135.6, 135.1, 129.2, 129.1, 129.0, 128.8, 126.6, 124.8, 123.3, 119.7, 50.5, 37.9, 34.0, 21.2, 21.2.

[0132] Example 18: Synthesis of 1,3-dipentylindene (4b):

[0133]

[0134] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, indene (0.3 molar parts), n-pentanol (1.5 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.3 molar parts) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4b (75.3 mg, colorless oil, 98% yield).

[0135] 1,3-dipentylindene (4b): 1 H NMR (400 MHz, Chloroform-d) δ 7.40 (d, J = 7.2 Hz, 1H), 7.32 - 7.25 (m, 2H) 7.22 - 7.16 (t, J = 8 Hz 1H), 6.21 (s, 1H), 3.43 - 3.33 (m, 1H), 2.52 (t, J = 7.6 Hz, 2H), 1.88 - 1.86 (m, 1H), 1.71 - 1.67 (m, 2H), 1.49 - 1.29 (m, 11H), 0.94 - 0.86 (m, 6H). 13 C NMR (100 MHz, Chloroform-d) δ 149.0, 145.3, 143.5, 133.2, 126.2, 124.6, 122.9, 119.1, 49.1, 32.4, 32.0, 31.9, 27.8, 27.8, 27.6, 22.7, 14.2.

[0136] Example 19: Synthesis of 4,4'-(1H-indene-1,3-diyl)bis(n,n-dimethylbutan-1-amine) (4c):

[0137]

[0138] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, indene (0.3 molar parts), 4-(dimethylamino)butan-1-ol (0.75 molar parts), PNP-Mn-1 (0.015 molar parts), KOH (0.1 mmol) and n-hexane (0.5 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 140 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4c (86.0 mg, yellow oil, 92% yield).

[0139] 4,4'-(1H-Indene-1,3-diyl)bis(n,n-dimethylbutan-1-amine) (4c): 1 H NMR (400 MHz, Chloroform-d) δ 7.41 (d, J = 7.3 Hz, 1H), 7.34 - 7.24 (m, 2H), 7.24 - 7.16 (m, 1H), 6.23 (s, 1H), 3.40 (d, J = 7.0 Hz, 1H), 2.56 (t, J = 7.5 Hz, 2H), 2.32 (t, J = 7.5 Hz, 2H), 2.23 (d, J = 5.6 Hz, 14H), 1.98 - 1.86 (m, 1H), 1.72 (p, J = 7.2 Hz, 2H), 1.63 - 1.56 (m, 2H), 1.56 - 1.36 (m, 5H). 13 C NMR (150 MHz, Chloroform-d) δ 148.8, 145.1, 143.3, 133.1, 126.3, 124.7, 122.9, 119.0, 60.0, 59.9, 49.0, 45.7, 45.7, 32.0, 28.3, 27.9, 27.7, 25.9, 25.8. ACPI-HRMS: m / z calculated for C21H35N2 [M+H] + : 315.2795; found: 315.2795.

[0140] Example 20: Synthesis of 1,3 - diisobutyl - 1H - indene (4d):

[0141]

[0142] The specific experimental procedure is as follows: In a glove box, to a dry, pressure-resistant sealed tube equipped with magnetic stirring, indene (0.3 mol equiv), isobutanol (1 mol equiv), PNP-Mn-1 (0.003 mol equiv), KOH (0.1 mol equiv) and n-hexane (1 mL) were added successively. Then the tube was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography using n-hexane eluent to obtain the target product of formula 4d (59.2 mg, yellow oil, 86% yield).

[0143] 1,3 - diisobutyl - 1H - indene (4d): 11H NMR (400 MHz, Chloroform-d) δ 7.43 (d, J = 7.3 Hz, 1H), 7.37 - 7.27 (m, 2H), 7.21 (td, J = 7.3, 1.5 Hz, 1H), 6.26 (d, J = 1.6 Hz, 1H), 3.55 - 3.44 (m, 1H), 2.44 (d, J = 7.1 Hz, 2H), 2.09 - 2.02 (m, 1H), 1.93 - 1.86 (m, 1H), 1.73 - 1.56 (m, 1H), 1.36 - 1.29 (m, 1H), 1.09 (d, J = 6.5 Hz, 3H), 1.01 (dd, J = 6.7, 2.4 Hz, 9H). 13 13C NMR (100 MHz, Chloroform-d) δ 149.5, 145.3, 142.2, 134.6, 126.2, 124.6, 123.0, 119.3, 47.3, 41.6, 37.3, 27.6, 27.3, 23.7, 23.1, 23.0, 22.7. ACPI-HRMS: m / z calculated for C17H25 [M+H] + : 229.1951,; found: 229.1950.

[0144] Example 21: Synthesis of 5,6-dichloro-1,3-dipentyl-1H-indene (4e):

[0145]

[0146] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, add 5,6-dichloroindene (0.3 molar parts), pentanol (0.66 molar parts), PNP-Mn-1 (0.015 molar parts), KOH (0.1 molar parts) and n-hexane (1 mL) in sequence. Then seal and take out, stir the reaction mixture at 100 °C for 1 h. After the reaction is completed, remove the solvent under reduced pressure, and the residue is separated by column chromatography with n-hexane eluent to obtain the target product of formula 4e (72.9 mg, yellow oil, 75% yield).

[0147] 5,6-dichloro-1,3-dipentyl-1H-indene (4e): 11H NMR (400 MHz, Chloroform-d) δ 7.42 (s, 1H), 7.32 (s, 1H), 6.23 (d, J = 1.7 Hz, 1H), 3.41 - 3.32 (m, 1H), 2.49 - 2.38 (m, 2H), 1.89 - 1.75 (m, 1H), 1.64 (dd, J = 9.4, 5.8 Hz, 2H), 1.42 - 1.24 (m, 11H), 0.90 (dt, J = 12.1, 6.9 Hz, 6H). 13 13C NMR (100 MHz, Chloroform-d) δ 148.7, 145.4, 142.5, 135.1, 130.3, 128.5, 124.8, 120.7, 48.9, 32.2, 31.9, 31.7, 27.6, 27.6, 27.2, 22.7, 14.2.

[0148] Example 22: Synthesis of 1,3-dipentyl-7-phenyl-1H-indene (4f):

[0149]

[0150] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 7-phenylindene (0.3 molar parts), pentanol (0.6 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.3 molar parts) and n-hexane (0.5 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4f (94.4 mg, yellow oil, 95% yield).

[0151] 1,3-dipentyl-7-phenyl-1H-indene (4f): 1 1H NMR (400 MHz, Chloroform-d) δ 7.52 (d, J = 7.3 Hz, 2H), 7.44 (t, J = 7.5 Hz, 2H), 7.37 (dd, J = 8.4, 6.5 Hz, 2H), 7.31 (d, J = 6.7 Hz, 1H), 7.16 (d, J = 7.3 Hz, 1H), 6.25 (s, 1H), 3.84 (d, J = 7.2 Hz, 1H), 2.56 (t, J = 7.7 Hz, 2H), 1.71 (q, J = 7.4 Hz, 2H), 1.42 (h, J = 4.8 Hz, 5H), 1.13 - 1.02 (m, 4H), 0.99 - 0.84 (m, 5H), 0.76 (t, J = 7.0 Hz, 3H). 1313C NMR (100 MHz, Chloroform-d) δ 146.0, 145.9, 143.2, 141.8, 138.1, 133.7, 128.5, 128.5, 127.1, 126.8, 125.9, 118.1, 48.5, 32.0, 31.8, 28.9, 27.8, 27.8, 26.4, 22.7, 22.4, 14.3, 14.1.

[0152] (III) Polyalkylindenes and Their Synthesis

[0153] Example 23: Synthesis of 1,3-bis(4-methylbenzyl)-2-methylindene (4g):

[0154]

[0155] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 molar portion), 4-methylbenzyl alcohol (0.75 molar portion), PNP-Mn-1 (0.003 molar portion), KOH (0.15 mmol), and n-hexane (0.5 mL) were added successively. Then the tube was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography using n-hexane as the eluent to obtain the target product of formula 4g (91.3 mg, colorless oil, 90% yield).

[0156] 1,3-bis(4-methylbenzyl)-2-methylindene (4g): 1 1H NMR (400 MHz, Chloroform-d) δ 7.05 (td, J = 6.4, 2.4 Hz, 1H), 6.99 - 6.86 (m, 9H), 6.81 (d, J = 8.1 Hz, 2H), 3.83 - 3.61 (m, 2H), 3.54 (dd, J = 8.4, 4.6 Hz, 1H), 3.30 (dd, J = 13.8, 4.8 Hz, 1H), 2.70 (dd, J = 13.8, 8.2 Hz, 1H), 2.27 (s, 3H), 2.22 (s, 3H), 2.02 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 146.3, 145.8, 143.0, 136.5, 136.4, 135.6, 135.5, 135.3, 129.2, 129.1, 128.8, 128.2, 126.5, 123.6, 123.3, 118.9, 53.3, 36.5, 30.8, 21.2, 21.1, 13.1. ACPI-HRMS: m / z calculated for C26H27 [M+H]+ : 339.2107; found: 339.2105.

[0157] Example 24: Synthesis of 1,3-dipentyl-2-methylindene (4h):

[0158]

[0159] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 molar parts), n-pentanol (1.5 molar parts), PNP-Mn-1 (0.003 molar parts), KOH (0.1 molar parts) and n-hexane (1 mL) were added successively. Then it was sealed and taken out. The reaction mixture was stirred at 130 °C for 1 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4h (74.5 mg, colorless oil, 92% yield).

[0160] 1,3-dipentyl-2-methylindene (4h): 1 H NMR (400 MHz, Chloroform-d) δ 7.36 (d, J = 7.4 Hz, 1H), 7.28 - 7.21 (m, 2H), 7.12 (td, J = 6.6, 2.3 Hz, 1H), 3.26 (t, J = 4 Hz, 1H), 2.51 (t, J = 7.6 Hz, 2H), 1.97 (s, 4H), 1.77 - 1.68 (m, 1H), 1.62 - 1.54 (m, 2H), 1.36 - 1.32 (m, 4H), 1.27 - 1.16 (m, 4H), 1.12 - 1.02 (m, 1H), 0.96 - 0.87 (m, 4H), 0.87 - 0.79 (m, 3H). 13 C NMR (100 MHz, Chloroform-d) δ 147.0, 146.4, 141.8, 136.9, 126.7, 123.5, 122.6, 118.2, 51.9, 32.4, 32.0, 30.0, 28.6, 25.3, 24.3, 22.8, 22.6, 14.3, 14.2, 12.5. ACPI-HRMS: m / z calculated for C20H31[M + H] + : 271.2420; found: 271.2420.

[0161] Example 25: Synthesis of 1,3-dipentyl-2-bromoindene (4i):

[0162]

[0163] The specific experimental procedures are as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 mol portion), n-pentanol (0.6 mol portion), PNP-Mn-1 (0.003 mol portion), KOH (0.03 mol portion) and n-hexane (1 mL) were added successively. Then, it was sealed and taken out. The reaction mixture was stirred at 120 °C for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4i (74.5 mg, colorless oil, 92% yield).

[0164] 1,3-Dipentyl-2-bromoindene (4i): 1 H NMR (400 MHz, Chloroform-d) δ 7.40 (d, J = 7.3 Hz, 1H), 7.34 - 7.28 (m, 2H), 7.22 (t, J = 7.2 Hz, 1H), 3.56 (t, J = 5.3 Hz, 1H), 2.70 - 2.58 (m, 2H), 2.10 - 1.99 (m, 1H), 1.96 - 1.85 (m, 1H), 1.65 (q, J = 7.5 Hz, 2H), 1.45 - 1.36 (m, 4H), 1.34 - 1.17 (m, 5H), 0.96 - 0.85 (m, 7H). 13 C NMR (100 MHz, Chloroform-d) δ 146.2, 143.9, 141.8, 128.0, 126.6, 124.7, 122.8, 118.8, 53.2, 32.2, 31.8, 30.1, 27.6, 26.8, 23.7, 22.7, 22.6, 14.2, 14.2.

[0165] Example 26: Synthesis of 2,2'-((2-methyl-1H-indene-1,3-diyl)bis(methylene))dipyridine (4j):

[0166]

[0167] The specific experimental procedures are as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 mol portion), pyridine-2-methanol (0.66 mol portion), PNP-Mn-1 (0.003 mol portion), KOH (0.09 mol portion) and n-hexane (1 mL) were added successively. Then, it was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4j (73.9 mg, light yellow oil, 79% yield).

[0168] 2,2'-((2-Methyl-1H-indene-1,3-diyl)bis(methylene))dipyridine (4j): 1 H NMR (400 MHz, Chloroform-d) δ 8.56 (dd, J = 22.1, 4.3 Hz, 2H), 7.51 - 7.40 (m, 2H), 7.18 - 7.02 (m, 4H), 6.97 (t, J = 7.3 Hz, 1H), 6.90 (d, J = 7.8 Hz, 1H), 6.78 (dd, J = 23.0, 7.6 Hz, 2H), 4.13 - 3.91 (m, 3H), 3.48 (dd, J = 13.6, 5.2 Hz, 1H), 2.91 (dd, J = 13.6, 8.6 Hz, 1H), 2.10 (s, 3H). 13 C NMR (100 MHz, Chloroform-d) δ 160.0, 159.9, 149.3, 149.2, 146.1, 145.5, 144.5, 136.6, 136.1, 134.0, 126.6, 124.1, 123.9, 123.1, 122.1, 121.6, 121.2, 119.1, 52.1, 39.6, 34.4, 13.1. ACPI-HRMS: m / z calculated for C22H21N2 [M+H] + : 313.1700,; found: 313.1700.

[0169] Example 27: Synthesis of 1,3-bis(4-bromobenzyl)-2-methylindene (4k):

[0170]

[0171] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 molar portion), 4-bromobenzyl alcohol (0.75 molar portion), PNP-Mn-1 (0.003 molar portion), KOH (0.1 molar portion) and n-hexane (1 mL) were added successively. Then the tube was sealed and taken out, and the reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of formula 4k (141.0 mg, pale yellow oil, 99% yield).

[0172] 1,3-bis(4-bromobenzyl)-2-methylindene (4k): 11H NMR (400 MHz, Chloroform-d) δ 7.33 - 7.23 (m, 4H), 7.19 - 7.11 (m, 2H), 7.10 - 7.05 (m, 1H), 6.91 (d, J = 7.8 Hz, 1H), 6.84 - 6.77 (m, 2H), 6.69 (d, J = 8.4 Hz, 2H), 3.82 - 3.64 (m, 2H), 3.61 (t, J = 6.0 Hz, 1H), 3.38 (dd, J = 13.8, 4.4 Hz, 1H), 2.89 (dd, J = 13.8, 7.3 Hz, 1H), 2.07 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 145.7, 145.6, 142.6, 138.4, 137.7, 135.5, 131.5, 131.1, 131.0, 129.9, 126.8, 124.0, 123.2, 120.2, 119.8, 119.0, 52.8, 36.0, 30.6, 13.1. ACPI-HRMS: m / z calculated for C24H21Br2 [M+H] + : 467.0005,; found: 467.0010.

[0173] Example 28: Synthesis of 1,3-bis(4-iodobenzyl)-2-methylindene (4l):

[0174]

[0175] The specific experimental procedure is as follows: In a glove box, to a dry, pressure-resistant sealed tube equipped with magnetic stirring, 2-methylindene (0.3 molar portion), 4-iodobenzyl alcohol (0.6 molar portion), PNP-Mn-1 (0.003 molar portion), KOH (0.09 molar portion) and n-hexane (1 mL) were added successively. Then the tube was sealed and taken out. The reaction mixture was stirred at 110 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure. The residue was separated by column chromatography using n-hexane eluent to obtain the target product of formula 4l (158.9 mg, pale yellow oil, 94% yield).

[0176] 1,3-bis(4-iodobenzyl)-2-methylindene (4l): 11H NMR (400 MHz, Chloroform-d) δ 7.51 (d, J = 8.3 Hz, 2H), 7.45 (d, J = 8.3 Hz, 2H), 7.21 - 7.03 (m, 3H), 6.91 (d, J = 7.5 Hz, 1H), 6.68 (d, J = 8.3 Hz, 2H), 6.57 (d, J = 8.3 Hz, 2H), 3.86 - 3.55 (m, 3H), 3.37 (dd, J = 13.8, 4.5 Hz, 1H), 2.88 (dd, J = 13.8, 7.3 Hz, 1H), 2.06 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 145.6, 145.6, 142.6, 139.1, 138.3, 137.5, 137.1, 135.4, 131.3, 130.3, 126.8, 124.0, 123.2, 119.0, 91.6, 91.1, 52.8, 36.0, 30.7, 13.1. APCI-HRMS: m / z calculated for C24H21I2 [M+H] + : 562.9727,; found: 562.9732.

[0177] (IV) Application of mono-alkyl indene compounds, namely 2-position selective functionalization of mono-alkyl indene compounds Edited by:

[0178] Example 29: Synthesis of 2-mesityl-3-(4-methylbenzyl)-1H-indene (5a) (2-position editable mesitylation of 3l):

[0179]

[0180] The specific experimental procedure is as follows: In a glove box, into a dry pressure-resistant sealed tube equipped with magnetic stirring, add 3l (0.25 mol portion), compound of formula 7 (0.375 mol portion), Pd(PPh 3 ) 4 (0.025 mol portion), K 2 CO 3 (0.75 mol portion) and toluene / water (1 mL / 0.1 mL). Then seal and take out, stir the reaction mixture at 90 °C for 4 h. After the reaction is completed, remove the solvent under reduced pressure, and elute the residue with n-hexane. The target product of formula 5a is obtained by column chromatography separation (63.4 mg, colorless oil, 75% yield).

[0181] 2-mesityl-3-(4-methylbenzyl)-1H-indene (5a): 11H NMR (400 MHz, Chloroform-d) δ 7.39 (d, J = 6.9 Hz, 1H), 7.18 - 7.07 (m, 3H), 6.92 (s, 4H), 6.84 (s, 2H), 3.58 (s, 2H), 3.49 (s, 2H), 2.24 (s, 3H), 2.19 (s, 3H), 2.02 (s, 6H). 13 13C NMR (100 MHz, Chloroform-d) δ 146.0, 143.6, 143.2, 138.4, 136.9, 136.7, 136.2, 135.3, 134.0, 133.8, 133.8, 129.0, 128.8, 128.7, 128.6, 128.2, 126.3, 124.3, 123.6, 120.4, 41.7, 32.1, 21.2, 21.1, 20.4. APCI-HRMS: m / z calculated for C26H27[M+H] + : 339.2107,; found: 339.2083.

[0182] Example 30: Synthesis of (E)-3-(4-methylbenzyl)-2-styryl-1H-indene (5b) (2-position editable styrylation of 3l):

[0183]

[0184] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, add 3l (0.25 mol equiv), compound of formula 8 (0.375 mol equiv), Pd(PPh 3 ) 4 (0.0125 mol equiv), K 2 CO 3 (0.75 mol equiv) and toluene / water (0.9 mL / 0.1 mL). Then seal and take out, stir the reaction mixture at 90 °C for 16 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is separated by column chromatography with n-hexane eluent to obtain the target product of formula 5b (75.4 mg white solid, 94% yield).

[0185] (E)-3-(4-methylbenzyl)-2-styryl-1H-indene (5b): 11H NMR (400 MHz, Chloroform-d) δ 7.48 (d, J = 7.7 Hz, 2H), 7.43 (d, J = 6.7 Hz, 1H), 7.35 (q, J = 7.8 Hz, 3H), 7.26 - 7.12 (m, 6H), 7.07 (d, J = 7.9 Hz, 2H), 6.84 (d, J = 16.0 Hz, 1H), 4.07 (s, 2H), 3.74 (s, 2H), 2.29 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 146.3, 142.6, 140.6, 140.4, 137.8, 136.4, 135.8, 129.4, 129.4, 128.8, 128.4, 127.6, 126.5, 126.5, 125.4, 123.6, 122.7, 119.9, 37.7, 31.1, 21.1. APCI-HRMS: m / z calculated for C25H23 [M+H] + : 323.1794,; found: 323.1780.

[0186] Example 31: Synthesis of 3-(4-methylbenzyl)-2-(4-phenylbut-1-ynyl)-1H-indene (5c) (Editable alkynylation at the 2-position of 3l):

[0187]

[0188] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, add 3l (0.25 mol equiv), compound of formula 9 (0.3 mol equiv), Pd(PPh 3 ) 2 Cl 2 (0.0125 mol equiv), CuI (0.025 mol equiv) and i Pr 2 NH (1.0 mL). Then seal and take out, stir the reaction mixture at 60 °C for 16 h. After the reaction is completed, remove the solvent under reduced pressure, and elute the residue with n-hexane. The target product of formula 5c is obtained by column chromatography separation (68.7 mg colorless oil, 79% yield).

[0189] 3-(4-methylbenzyl)-2-(4-phenylbut-1-ynyl)-1H-indene (5c): 11H NMR (400 MHz, Chloroform-d) δ 7.47 - 7.42 (m, 1H), 7.35 (d, J = 5.9 Hz, 4H), 7.31 - 7.23 (m, 6H), 7.15 (d, J = 8.1 Hz, 2H), 4.06 (s, 2H), 3.57 (s, 2H), 3.01 (t, J = 7.3 Hz, 2H), 2.85 (t, J = 7.3 Hz, 2H), 2.38 (s, 3H). 13 13C NMR (100 MHz, Chloroform-d) δ 147.3, 144.6, 142.7, 140.8, 136.3, 135.6, 129.2, 128.7, 128.6, 128.5, 126.5, 126.4, 125.5, 123.9, 123.5, 120.2, 96.6, 78.4, 41.8, 35.4, 32.9, 22.3, 21.2. APCI-HRMS: m / z calculated for C27H25[M+H] + : 349.1951,; found: 349.1945.

[0190] Example 32: Synthesis of 4,4,5,5-tetramethyl-2-(3-(4-methylphenyl)-1H-inden-2-yl)-1,3,2-dioxaborolane (5d) (Editable boronation at the 2-position of 3l):

[0191]

[0192] Specific experimental procedures are as follows: In a glove box, sequentially add 3I (0.25 molar parts), the compound of formula 10 (0.375 molar parts), Pd(PPh 3 ) 2 Cl 2 (0.0125 molar parts), triethylamine (0.75 molar parts) and 1,4-dioxane (1.0 mL) to a dry pressure-resistant sealed tube equipped with magnetic stirring. Then seal and take out, stir the reaction mixture at 80 °C for 6 h. After the reaction is completed, remove the solvent under reduced pressure, and elute the residue with n-hexane. The target product of formula 5d is obtained by column chromatography separation (69.5 mg white solid, 75% yield).

[0193] 4,4,5,5-tetramethyl-2-(3-(4-methylphenyl)-1H-inden-2-yl)-1,3,2-dioxaborolane (5d): 1HNMR(400MHz, Chloroform-d) δ 7.46 (dd, J = 6.3, 2.3Hz, 1H), 7.39 - 7.31 (m, 1H), 7.26 - 7.22 (m, 2H), 7.22 - 7.17 (m, 2H), 7.06 (d, J = 7.8Hz, 2H), 4.29 (s, 2H), 3.56 (s, 2H), 2.29 (s, 3H), 1.35 (d, J = 1.5Hz, 12H). 13 C NMR(100MHz, Chloroform-d) δ 156.9, 147.1, 145.9, 137.3, 135.3, 129.1, 128.7, 126.0, 125.8, 123.9, 121.1, 83.2, 41.4, 33.7, 25.0, 21.1. ACPI-HRMS: m / z calculated for C23H28BO2 [M+H] + : 347.2176,; found: 347.2155.

[0194] Example 33: Synthesis of 4-methyl-N-(3-(4-methylphenyl)-1H-inden-2-yl)benzamide (5e) (editable amidation at the 2-position of 3l):

[0195]

[0196] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, add 3l (0.3 molar portion), compound of formula 11 (0.45 molar portion), CuI (0.015 molar portion), K 2 CO 3 (0.45 molar portion) and toluene (1.0 mL). Then seal and take out, stir the reaction mixture at 100 °C for 5 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is separated by column chromatography using n-hexane eluent to obtain the target product of formula 5e (59.1 mg light yellow solid, 67% yield).

[0197] 4-methyl-N-(3-(4-methylphenyl)-1H-inden-2-yl)benzamide (5e): 1 H NMR(400MHz, Chloroform-d) δ 7.78 (s, 1H), 7.46 (d, J = 7.3Hz, 1H), 7.36 - 7.26 (m, 4H), 7.24 - 7.14 (m, 6H), 4.19 (s, 2H), 3.93 (s, 2H), 2.39 (d, J = 4.6Hz, 6H). 1313C NMR (100 MHz, Chloroform-d) δ 163.9, 144.7, 142.4, 139.4, 139.3, 136.8, 135.1, 131.4, 130.1, 129.3, 129.1, 127.1, 126.5, 124.0, 123.5, 120.7, 117.8, 39.2, 30.9, 21.6, 21.2. ESI-HRMS: m / z calculated for C25H23NO [M+Na] + : 376.1672,; found: 376.1669.

[0198] (V) Application of single-alkyl indene compounds in the synthesis of rhodium catalysts:

[0199] Example 34: Synthesis of monovalent rhodium complex (3a-Rh), the reaction formula is as follows:

[0200]

[0201] The specific experimental operation is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, successively add indene shown in 3a (0.28 mol portion), catalyst precursor shown in [Rh(COD)Cl] 2 (0.153 mol portion), KO t Bu (0.38 mol portion) and tetrahydrofuran (4 mL). Then seal and take out, stir the reaction mixture at room temperature for 18 h. After the reaction is completed, remove the solvent under reduced pressure, and the residue is eluted with n-hexane and separated by column chromatography to obtain the target product of formula 3a-Rh (84.3 mg, yellow solid, 70% yield).

[0202] 3a-Rh complex: 1 1H NMR (400 MHz, Chloroform-d) δ 7.22 - 7.15 (m, 2H), 7.13 - 7.01 (m, 6H), 5.98 (s, 1H), 5.07 (d, J = 2.8 Hz, 1H), 3.91 - 3.83 (m, 2H), 3.68 - 3.62 (m, 2H), 3.62 - 3.47 (m, 2H), 2.28 (s, 3H), 1.93 - 1.84 (m, 4H), 1.82 - 1.67 (m, 4H). 13 13C NMR (100 MHz, Chloroform-d) δ 137.6, 135.6, 129.2, 128.2, 122.5, 122.4, 119.7, 117.9, 113.0, 112.6, 93.6 (d, J C-Rh = 5 Hz), 74.3 (d, J C-Rh= 4 Hz), 70.7 (d, J C-Rh = 14 Hz), 68.2 (d, J C-Rh = 14 Hz), 32.0, 31.8, 31.1, 21.1. ESI-HRMS: m / z calculated for C25H27Rh [M] + : 430.1162; found: 430.1155.

[0203] Example 35: Synthesis of monovalent rhodium complex (3h-Rh), the reaction formula is as follows:

[0204]

[0205] The specific experimental operation is as follows: In the glove box, to a dry, pressure-resistant sealed tube equipped with magnetic stirring, successively add indene (0.28 mol portion) shown in 3h, the catalyst precursor shown in [Rh(COD)Cl] 2 (0.153 mol portion), KO t Bu (0.38 mol portion) and tetrahydrofuran (4 mL). Then seal and take out, stir the reaction mixture at room temperature for 18 h. After the reaction is completed, remove the solvent under reduced pressure. The residue is eluted with n-hexane and separated by column chromatography to obtain the free 3h-Rh target product of the formula. Then, add 0.12 mmol of hydrochloric acid to the n-hexane solution of 3h-Rh, and remove the solvent under reduced pressure to obtain the 3h-Rh hydrochloride target product of the formula.

[0206] 3h-Rh complex: 1 H NMR (400 MHz, Chloroform-d) δ 8.65 (s, 3H), 7.66 - 7.33 (m, 4H), 7.27 - 7.08 (m, 5H), 6.21 (d, J = 9.0 Hz, 1H), 4.28 (s, 1H), 4.16 (s, 2H), 3.68 (d, J = 8.9 Hz, 1H), 3.24 (d, J = 8.8 Hz, 2H), 2.81 - 2.06 (m, 7H), 1.68 (t, J = 8.8 Hz, 2H), 1.26 (d, J = 8.4 Hz, 2H), 0.87 (d, J = 8.1 Hz, 1H). 1313C NMR (100 MHz, Chloroform-d) δ 145.0, 144.4, 142.3, 136.3, 129.2, 129.2, 128.8, 127.7, 126.2, 124.8, 123.8, 119.1, 78.7, 67.2, 56.2, 37.9, 32.8, 31.7, 31.0, 31.0, 24.0, 22.8, 14.2. ESI-HRMS: m / z calculated for C26H31ClNRh [M-Cl] + : 460.1506,; found: 460.1509.

[0207] Furthermore, the catalytic activity of the 3h-Rh complex synthesized in Example 35 was tested, and the 3h-Rh complex was used for the synthesis of 1-phenyl-3-(4-methylphenyl)propan-1-ol (13)

[0208]

[0209] The specific experimental procedure is as follows: In a glove box, into a dry, pressure-resistant sealed tube equipped with magnetic stirring, 1-phenylethanol (Formula 12, 0.3 molar portion), primary benzyl alcohol (Formula 2a, 0.45 molar portion), NaO t Bu (0.15 molar portion), catalyst (3h-Rh, 0.006 molar portion) and toluene (1 mL) were added in sequence. Then the tube was sealed and taken out, and the reaction mixture was stirred at room temperature for 18 h. After the reaction was completed, the solvent was removed under reduced pressure, and the residue was separated by column chromatography with n-hexane eluent to obtain the target product of Formula 13 (56.0 mg, colorless oil, 82% yield).

[0210] 1-phenyl-3-(4-methylphenyl)propan-1-ol (13): 1 1H NMR (400 MHz, Chloroform-d) δ 7.34 (dd, J = 4.5, 2.0 Hz, 4H), 7.29 - 7.22 (m, 1H), 7.08 (d, J = 2.0 Hz, 4H), 4.67 (dt, J = 5.6, 2.9 Hz, 1H), 2.76 - 2.55 (m, 2H), 2.31 (d, J = 2.1 Hz, 3H), 2.18 - 1.94 (m, 2H), 1.87 (s, 1H). 13 13C NMR (100 MHz, Chloroform-d) δ 144.8, 138.8, 135.4, 129.2, 128.6, 128.5, 127.7, 126.1, 40.7, 31.7, 21.1.

[0211] It is understandable that the above specific description of the present invention is only for the purpose of illustrating the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those of ordinary skill in the art should understand that partial modifications or equivalent replacements can still be made to the present invention to achieve the same technical effects; as long as the use requirements are met, they are all within the protection scope of the present invention.

Claims

1. An alkyl indene compound, characterized in that: The general structure is as follows: Among them, R 1 Represents one or two substituents on the connected benzene ring, each R 1 The substituents are independently selected from hydrogen, halogen, C1-C6 alkyl, C1-C6 alkoxy, aryl, nitro, cyano or ester; R 2 Derived from hydrogen, aralkyl, heteroaralkyl, C1-C 12 Alkyl or alkyl containing functional group; R 3 R is selected from hydrogen, halogen, hydroxyl, amine, C1-C6 alkyl, alkenyl, alkynyl or aryl; 4 Derived from aralkyl, heteroaralkyl, C1-C 12 Alkyl or alkyl containing functional group; when R 2 When it is not hydrogen, R 4 Equivalent to R 2 .

2. The alkyl indene compound according to claim 1, characterized in that: R 1 It is hydrogen, fluorine, chlorine, bromine, C1-C6 alkyl, methoxy or aryl.

3. The alkyl indene compound according to claim 1, characterized in that: R 2 R is hydrogen, butyl, pentyl, hexyl, isobutyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 4-ene-hexyl, benzyl, a phenyl ring containing a substituent (the substituent is methyl, methoxy, fluorine, chlorine, bromine, iodine or trifluoromethyl), 2-pyridylmethyl or 2-furylmethyl; 4 is butyl, pentyl, hexyl, isobutyl, cyclopropylmethyl, cyclobutylmethyl, cyclopentylmethyl, cyclohexylmethyl, 4-ene-hexyl, benzyl, a phenyl ring containing a substituent (the substituent is methyl, methoxy, fluorine, chlorine, bromine, iodine or trifluoromethyl), 2-pyridylmethyl or 2-furylmethyl; when R 2 When it is not hydrogen, R 4 Equivalent to R 2 .

4. The alkyl indene compound according to claim 1, characterized in that: R 3 is hydrogen, bromine, methyl, hydroxyl, amino, alkenyl, alkynyl or aryl.

5. A modular alkyl editing synthesis method of the alkyl indene compound according to any one of claims 1 to 4, characterized in that: The method uses indene and alcohol as raw materials, tridentate Mn as catalyst under alkaline conditions, and a hydrogen borrowing strategy under heating conditions to carry out modular alkyl editing synthesis to obtain mono-alkyl indene compounds or di / poly-alkyl indene compounds.

6. The modular alkyl editing synthesis method of alkyl indenes according to claim 5, characterized in that: When the product is a mono-alkyl indene compound, the synthesis method is as follows: 0.3 molar parts of alcohol, 0.3-0.6 molar parts of indene, 0.003-0.015 molar parts of PNP-Mn, 0.03-0.3 molar parts of alkali and an organic solvent are mixed, and stirred at 80-140° C. for 1-24 hours. After the reaction is completed, the organic solvent is removed under reduced pressure, and the residue is separated by column chromatography using n-hexane as an eluent to obtain the mono-alkyl indene compound.

7. The modular alkyl editing synthesis method of alkyl indenes according to claim 5, characterized in that: When the product is a dialkyl indene compound, the synthesis method thereof is as follows: when the 2-position of indene does not contain a methyl group, 0.6-1.5 molar parts of alcohol, 0.3 molar parts of indene, 0.003-0.015 molar parts of PNP-Mn, 0.03-0.3 molar parts of a base and an organic solvent are mixed, and the mixture is stirred at 100-140° C. for 1-24 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography using n-hexane as an eluent to obtain the dialkyl indene compound.

8. The modular alkyl editing synthesis method of alkyl indenes according to claim 5, characterized in that: When the product is a polyalkyl indene compound, the synthesis method is as follows: when the 2-position of indene contains a methyl group, 0.6-1.5 molar parts of alcohol, 0.3 molar parts of indene, 0.003-0.015 molar parts of PNP-Mn, 0.03-0.3 molar parts of a base and an organic solvent are mixed, and the mixture is stirred at 100-140° C. for 1-24 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography using n-hexane as an eluent to obtain the polyalkyl indene compound.

9. An application of the alkyl indene compound according to claims 1-4, characterized in that: The mono-alkyl indene compounds are further transformed with substituted boronic acid (or alkyne or amide) derivatives to achieve selective functionalization editing of the 2-position of the mono-alkyl indene compounds, thereby obtaining indene compounds with diversified functional groups at the 2-position.

10. An application of the alkyl indene compound according to claims 1-4, characterized in that: The mono-alkyl indene compound is used to synthesize the rhodium catalyst, which comprises 0.2-0.3 mole parts of the mono-alkyl indene compound, 0.1-0.2 mole parts of [Rh(COD)2Cl]2, and KO t 0.3-0.4 molar parts of Bu and THF are placed in a sealed tube, and the mixture is reacted at room temperature for 10-24 hours. After the reaction is completed, the solvent is removed under reduced pressure, and the residue is separated by column chromatography to obtain a catalyst precursor of formula 3-Rh.

Images