Chiral fluorene containing 9-position quaternary carbon stereogenic center and preparation method therefor

Abstract

Provided are a chiral fluorene containing 9-position quaternary carbon stereogenic center and a preparation method therefor. The method comprises: under the catalysis by chiral phosphoric acid, performing ring-opening desymmetrization on a fluorene-derived epoxy compound by means of using a mercaptobenzothiazole type nucleophilic reagent to obtain a chiral fluorene product at excellent separation yield and enantioselectivity, namely general formula (1) in which the definitions of substituents are same as that in claim 1. The preparation method involves mild reaction conditions and uses a small amount of a catalyst. In the aspect of uses, the chiral spirofluorene can be used as a potential OLED electron transport material, a fluorescent probe, a fluorescent dye, etc., and can also be used as a monomer to synthesize polyfluorene for use in fields similar to the described fields.

Description

A chiral fluorene containing a 9-quaternary carbon stereo center and a preparation method thereof Technical Field

[0001] The present invention relates to synthesizing a novel chiral fluorene derivative by utilizing an asymmetric catalytic method. The present invention also relates to a part of the product having a high fluorescence quantum yield and having potential value as an OLED luminescent material. Background Art

[0002] In recent decades, the field of organic light-emitting diodes (OLEDs) has made rapid progress and has become one of the most promising technologies for full-color display and lighting applications. Fluorene, as one of the most commonly used building blocks in the synthesis of OLED materials, has been widely used. However, the 9-position of fluorene compounds is susceptible to oxidative degradation, which can alter device spectral properties and shorten device life. Therefore, quaternization of the 9-position of fluorene compounds can improve material stability and solubility during the preparation process.

[0003] Chiral fluorene containing 9-quaternary carbon has important application value in the synthesis of chiral functional materials, but the related monomers are mainly obtained by chiral HPLC separation, and there are few reports on the use of asymmetric catalysis. The only methods currently available include the asymmetric Csp 2 -H insertion (Nat. Commun. 2020, 11, 2363-2372; Chem. Sci. 2022, 13, 1992-2000) and by remote Suzuki coupling (J. Am. Chem. Soc. 2022, 144, 123-129).

[0004] Summary of the Invention

[0005] The purpose of the present invention is to solve the challenges of constructing 9-quaternary carbon chiral fluorene and the shortcomings of the synthesis method in the prior art. The present invention provides a preparation method of chiral fluorene containing a 9-quaternary carbon stereo center.

[0006] The technical solution adopted by the present invention is: using a mercaptobenzothiazole nucleophilic reagent to perform ring-opening desymmetrization on a fluorene-derived prochiral epoxy compound in an organic solvent to generate a chiral fluorene with a discontinuous chiral center;

[0007] Among them, R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 9、R 10 、R 11 、R 12 At least one of alkyl or perfluoroalkyl, substituted alkyl, alkoxy, substituted alkoxy, alkylthio, substituted alkylthio, aryl, substituted aryl, heteroaryl, substituted heteroaryl, halogen, hydroxy, alkenyl, alkynyl, nitro, borate, amino, aminoalkoxycarbonyl and hydrogen;

[0008] X is one of S, N, and O;

[0009] A is one of carbon and silicon.

[0010] Further: R 1 -R 12 are independently selected from C1-C 20 Alkyl, substituted C1-C 20 Alkyl, C1-C 20 Alkoxy, substituted C1-C 20 Alkoxy, C1-C 20 Alkylthio, substituted C1-C 20 Alkylthio, C6-C 20 Aryl, substituted C6-C 20 Aryl, C4-C 20 Heteroaryl, substituted C4-C 20 Heteroaryl, C1-C 20 Substituted alkenyl, C1-C 20 Substituted alkynyl, C1-C 20 One or more combinations of substituted aminoalkoxycarbonyl, borate, hydroxy, amino, nitro, halogen and hydrogen.

[0011] The substituents in the above-mentioned substituted alkyl, substituted alkoxy, substituted alkylthio, substituted aryl and substituted heteroaryl are selected from halogen, N-dimethylamino, C1-C4 alkyl, halogen-substituted C1-C4 alkyl, C3-C6 cycloalkyl, halogen-substituted C3-C6 cycloalkyl, C1-C4 alkoxy, halogen-substituted C1-C4 alkoxy, methylenedioxy, C6-C 16 Aryl, C6-C containing C1-C5 alkyl substituted 16 Aryl, C6-C 16 At least one of an aryloxy group, a cyano group, a nitro group, a hydroxyl group, an amino group, and a carboxyl group.

[0012] The preparation method of chiral fluorene containing 9-quaternary carbon stereo center is as follows:

[0013] Under the catalysis of chiral phosphoric acid, mercaptobenzothiazole nucleophiles are used in organic solvents to perform ring-opening desymmetrization on fluorene-derived epoxides to generate the chiral fluorene with discontinuous chiral centers:

[0014] Furthermore, the structure of the fluorene-derived epoxy compound is:

[0015] and

[0016] R 1 -R 8 The substituents are as defined above.

[0017] Furthermore, the chiral phosphoric acid catalyst may have the following three structures or their corresponding enantiomers:

[0018] wherein R=one of 2,4,6-triisopropylphenyl, 2,4,6-tricyclohexylphenyl, 2,6-diisopropyl-4-(1-adamantyl)phenyl, 2,6-diisopropyl-4-(9-anthryl)phenyl, and 3,5-diisopropylphenyl, with 2,6-diisopropyl-4-(9-anthryl)phenyl being preferred;

[0019] Furthermore, the specific structure of the chiral phosphoric acid catalyst is:

[0020] Furthermore, the amount of the chiral phosphoric acid catalyst used is 10 to 0.1 mol%, preferably 0.1 mol%.

[0021] Furthermore, in order to obtain better enantiomeric selectivity, the reaction temperature can be in the range of 0 to -30°C, with -30°C being preferred.

[0022] Furthermore, the molar ratio of the mercaptobenzothiazole nucleophile to the epoxy compound electrophile is 1 to 1.1:1, with a preferred molar ratio of 1.1:1.

[0023] Furthermore, the reaction solvent can be xylene, toluene, dichloromethane, chloroform, or ethyl acetate, with xylene being preferred.

[0024] Furthermore, the concentration of the epoxy compound 1 in xylene is 0.1-0.2 mol / L, preferably 0.1 mol / L.

[0025] The concentration of mercaptobenzothiazole in xylene in the solvent is 0.11-0.22 mol / L, preferably 0.11 mol / L.

[0026] Compared with the prior art, the present invention offers the following advantages: Using mercaptobenzothiazole nucleophiles as catalyzers for chiral phosphoric acid, the present invention performs ring-opening desymmetrization of fluorene-derived epoxy compounds, yielding chiral fluorenes containing a 9-position quaternary carbon stereocenter with excellent isolation yield and enantioselectivity. The reaction conditions are mild and the catalyst usage is minimal. In terms of applications, the chiral spirofluorenes provided by the present invention can be used as potential electron transport materials for organic light-emitting diodes (OLEDs), fluorescent probes, fluorescent dyes, and as monomers for the synthesis of polyfluorenes, with applications in similar fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a graph showing the fluorescence quantum yield of chiral fluorene 3y (10 μM dichloromethane solution);

[0028] Figure 2 Fluorescence quantum yield of chiral fluorene 3za (10 μM dichloromethane solution);

[0029] Figure 3 Fluorescence quantum yield of chiral fluorene 3zb (10 μM water / tetrahydrofuran mixed solution (volume ratio = 99:1));

[0030] Figure 4 shows the fluorescence quantum yield of chiral fluorene 3zf (10 μM dichloromethane solution);

[0031] Figure 5 shows the aggregation-induced emission measurement of chiral fluorene 3zb;

[0032] Figure 6 Aggregation-induced emission images of chiral fluorene 3zb;

[0033] Figure 7 Energy level determination diagram of chiral fluorene 3za. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with specific embodiments.

[0035] Compound Synthesis Method: Fluorene-derived epoxide 1 (0.1 mmol, 1 equiv), mercaptobenzothiazole 2 (0.11 mmol, 1.1 equiv), and xylene (1.0 mL) were added sequentially to a 4 mL vial equipped with a magnetic stirrer. The resulting suspension was cooled to -30°C, and the optimal catalyst C1 (0.1 mg, 0.1 mol%) was added with stirring. The reaction was maintained at the same temperature for 24 hours, with thin-layer chromatography (TLC) monitoring the reaction progress. After completion, the reaction was directly chromatographed on a silica gel column (eluent: PE / EA = 10:1) to obtain the desired product.

[0036] The specific preparation methods of the novel compounds of the present invention are described below using several synthesis examples as examples, but the preparation methods of the present invention are not limited to these synthesis examples. The solvents and reagents used in the examples of the present invention can be purchased from domestic chemical product markets, such as Sinopharm Group Reagent Co., Ltd., TCI Corporation, Shanghai Bid Pharmaceutical Co., Ltd., and J&K Reagent Co., Ltd.

[0037] Example 1: Synthesis of chiral fluorene 3a

[0038] The product is a white solid (38.1 mg, 95% yield, 91% ee)

[0039] The characterization data are as follows:

[0040] 1 H NMR (400MHz, CDCl3): δ7.78–7.77(m,1H),7.73–7.71(m,2H),7.68–7.67(m,1H),7.62–7.60(m,1H),7.50–7.48(m,1H),7.42–7.34(m,3H), 7.33–7.24(m,3H),7.87–7.86(m,1H),4.91–4.89(m,1H),4.54–4.48(m,1H),2.94–2.84(m,1H),2.54–2.46(m,1H),2.19–2.10(m,2H)ppm.

[0041] 13 C NMR (100MHz, CDCl3): δ167.9,152.3,149.2,147.7,140.9,140.6,135.1,127.6(Two C),127.3,126.3,125.0,124.8,122.3,121.2(Two C),121.0,120.2,119.9,87.8, 62.46,53.2,35.3,29.2ppm.

[0042] HRMS(ESI+)Calcd for C 24 H 20 NOS2[M+H] + :402.0981,found:402.0977.

[0043] Example 2: Synthesis of chiral fluorene 3b

[0044] The product was a white solid (24h, 40.4 mg, 84% yield, 93% ee).

[0045] The characterization data are as follows:

[0046] 1 H NMR (400MHz, CDCl3): δ7.92–7.90(m,1H),7.82–7.78(m,2H),7.68–7.66(m,2H),7.57–7.55(m,1H),7.49–7.45(m,2H),7.40–7.34(m,3 H),6.59(s,1H),5.02–4.96(m,1H),4.54–4.47(m,1H),2.73–2.68(m,1H),2.56–2.50(m,1H),2.41–2.36(m,1H),2.29–2.22(m,1H)ppm.

[0047] 13 C NMR (100MHz, CDCl3): δ167.9,153.9,152.3,152.0,138.7,138.3,135.2,130.7,128.4,127.7,126.5(two C),125.0,123.9,121.4,121.2,121.2,121.2,119.8,81.5,55.9,54.4,45.8,43.1ppm.

[0048] HRMS(ESI+)Calcd for C 24 H 19 BrNOS2[M+H] + :480.0086,found:480.0087.

[0049] Example 3: Synthesis of Chiral Fluorene 3c

[0050] The product was a white solid (24 h, 46 mg, 95% yield, 85% ee).

[0051] The characterization data are as follows:

[0052] 1 H NMR (400MHz, CDCl3): δ7.94–7.91(m,2H),7.79–7.77(m,1H),7.68–7.66 (m,1H),7.57–7.45(m,4H),7.37–7.34(m,3H),6.54(s,1H),5.03–4.97(s,1H),4.50–4.4 4(m,1H),2.72–2.67(m,1H),2.69–2.54(m,1H),2.40–2.35(m,1H),2.28–2.22(m,1H)ppm.

[0053] 13 C NMR (100MHz, CDCl3): δ167.8,154.3,152.3,151.7,138.6,138.4,135.1,130.6,128.3,127.7,1 27.2,126.5,125.0,123.1,121.6,121.3,121.2,121.1,119.9,81.5,55.9,54.4,45.9,43.0ppm.

[0054] HRMS(ESI+)Calcd for C 24 H 19 BrNOS2[M+H] + :480.0086,found:480.0084.

[0055] Example 4: Synthesis of Chiral Fluorene 3d

[0056] The product was a white solid (24h, 45.4 mg, 95% yield, 95% ee).

[0057] The characterization data are as follows:

[0058] 1 H NMR (400MHz, CDCl3): δ7.93–7.91(m,1H),7.85–7.83(m,1H),7.80–7.73(m,4H),7.69–7.67(m,2H),7.63–7.60(m,1H),7.50–7.46(m,3H),7.42– 7.34(m,4H),6.60(s,1H),5.11–5.06(m,1H),4.59–4.53(m,1H),2.83–2 .77(m,1H),2.65–2.69(m,1H),2.49–2.43(m,1H),2.35–2.31(m,1H)ppm.

[0059] 13 C NMR (100MHz, CDCl3): δ168.1,152.6,152.5,152.3,141.4,141.1,139.1,138.9,135.2,128.9,128.0,127.6,1 27.4,127.2,126.7,126.5,124.9,123.8,121.9,121.2,121.2,120.2,119.9,81.8,55.9,54.6,46.1,43.3ppm.

[0060] HRMS(ESI+)Calcd for C 30 H 24 NOS2[M+H] + :478.1294,found:478.1288.

[0061] Example 5: Synthesis of Chiral Fluorene 3e

[0062] The product was a white solid (24h, 40.1 mg, 84% yield, 89% ee).

[0063] The characterization data are as follows:

[0064] 1 H NMR (300MHz, CDCl3): δ8.00(s,1H),7.93–7.90(m,1H),7.80–7.76(m,3H),7.73–7.68(m,2H),7.63–7.57(m,2H),7.50–7.45(m, (-OH) is not shown)

[0065] 13 C NMR (100MHz, CDCl3): δ168.0,153.0,152.5,152.3,141.4,141.2,139.3,138.6,135.2,128.8,127.9,127.6,127.3(two C),126.7,126.5,124.9,123.2,122.5,121.2(two C),120.0,119.9,81.6,55.7,54.4,46.3,43.1ppm.

[0066] HRMS(ESI+)Calcd for C 30 H 24 NOS2[M+H] + :478.1294,found:478.1291.

[0067] Example 6: Synthesis of Chiral Fluorene 3f

[0068] The product was a white solid (24h, 50.2 mg, 86% yield, 88% ee).

[0069] The characterization data are as follows:

[0070] 1 H NMR (400MHz, CDCl3): δ7.84-7.82(m,1H),7.74-7.63(m,5H),7.43-7.46(m,3H),7.43-7.37(m,3H),7.34-7.24 (m,6H),7.01-6.99(m,2H),6.53(s,1H),5.04(s,2H),5.01-4.96(m,1H),4.49-4.43(m,1H),2.72-2.66(m,1H), 2.55-2.49(m,1H),2.38-2.33(m,1H),2.27-2.21(m,1H)ppm.

[0071] 13 C NMR (100MHz, CDCl3): δ168.1,158.4,152.6,152.4,152.3,140.6,139.1,138.3,137.0,135.2,134.1,128.7,128.3(two C),128.1,127.8,127.5,126.5,126.3,124.9,123.8,121.5,121.21,121.18,120.1,119.8,115.3,81.8,70.1,55.9,54.5,46.1,43.3ppm.

[0072] HRMS(ESI+)Calcd for C 37 H 30 NO2S2[M+H] + :584.1712,found:584.1712.

[0073] Example 7: Synthesis of chiral fluorene 3g

[0074] The product was a white solid (24h, 44.4 mg, 76% yield, 97% ee).

[0075] The characterization data are as follows:

[0076] 1H NMR (300MHz, CDCl3): δ7.98(s,1H),7.94–7.92(m,1H),7.80–7.72(m,3H),7.65–7.62(m,2H),7.59–7.57(m,2H),7.47–7.34(m,9H),7. 11–7.08(m,2H),5.13(s,2H),5.09–5.04(m,1H),4.61–4.53(m,1H),2.78–2.66(m,2H),2.57–2.50(m,1H),2.33–2.25(m,1H)ppm.(-OH is not shown)

[0077] 13 C NMR (100MHz, CDCl3): δ168.1,158.5,153.0,152.5,152.3,140.7,139.4,138.1,137.0,135.2,134.2,128.7(two C),128.3,128.0,127.8,127.6(two C),126.5,126.2,125.0,123.2,122.0,121.2,120.1,119.9,115.3,81.6,70.1,55.7,54.5,46.4,43.1ppm.

[0078] HRMS(ESI+)Calcd for C 37 H 30 NO2S2[M+H] + :584.1712,found:584.1712.

[0079] Example 8: Synthesis of Chiral Fluorene 3h

[0080] The product was a white solid (24h, 46.7 mg, 95% yield, 95% ee).

[0081] The characterization data are as follows:

[0082] 1H NMR (400MHz, CDCl3): δ7.91–7.89(m,1H),7.80–7.71(m,5H),7.59–7.55(m,3H),7.48–7.44(m,1H),7.38–7.35(m,3H),7.28–7.26(m,2H),6.5 8(s,1H),5.09–5.03(m,1H),4.57–4.50(m,1H),2.80–2.74(m,1H),2.6 3–2.57(m,1H),2.46–2.42(m,1H),2.41(s,3H),2.35–2.29(m,1H)ppm.

[0083] 13 C NMR (100MHz, CDCl3): δ168.1,152.53,152.45,152.3,141.0,139.1,138.6,138.5,137.2,135.2,129.6,127.9(two C),127.5,127.1,126.5,124.9,123.8,121.7,121.2,121.19,120.1,119.8,81.8,55.9,54.5,46.1,43.3,21.2ppm.

[0084] HRMS(ESI+)Calcd for C 31 H 26 NOS2[M+H] + :492.1450,found:492.1442

[0085] Example 9: Synthesis of Chiral Fluorene 3i

[0086] The product was a white solid (24h, 46.2 mg, 94% yield, 88% ee).

[0087] The characterization data are as follows:

[0088] 1 H NMR (300MHz, CDCl3): δ8.00–7.93(m,2H),7.83–7.77(m,3H),7.60–7.48(m,5H),7.41–7.39(m,3H),7.31–7.29(m,2H) ,5.09–5.07(m,1H),4.61–4.53(m,1H),2.78–2.68(m,2H),2.57–2.50(m,1H),2.43(s,3H),2.35–2.27(m,1H)ppm.(-OH is not shown)

[0089] 13 C NMR (75MHz, CDCl3): δ168.0,152.9,152.5,152.3,141.1,139.3,138.5,138.3,137.1,135.2,129.6,127.8,127.5(two C),127.1,126.5(two C),124.9,123.1,122.2,121.2,120.0,119.8,81.6,55.6,54.4,46.3,43.1,21.1ppm.

[0090] HRMS(ESI+)Calcd for C 31 H 26 NOS2[M+H] + :492.1450,found:492.1445

[0091] Example 10: Synthesis of Chiral Fluorene 3j

[0092] The product was a white solid (24h, 40.6 mg, 82% yield, 88% ee).

[0093] The characterization data are as follows:

[0094] 1 H NMR (300MHz, CDCl3): δ7.95–7.92(m,1H),7.86–7.72(m,5H),7.67–7.62(m,2H),7.59–7.56(m,1H),7.53–7.47(m,1H),7.41–7.36(m,3H),7. 21–7.15(m,2H),5.12–5.05(m,1H),4.62–4.53(m,1H),2.83–2.76(m,1H),2.68–2.61(m,1H),2.50–2.43(m,1H),2.39–2.30(m,1H)ppm.(-OH is not shown)

[0095] 13 C NMR (100MHz, CDCl3): δ168.0,162.5(d, 1 J C‐F =245Hz),152.6,152.4,152.3,140.0,138.95,138.90,137.5(d, 4 J C‐F =3Hz),135.2,128.8(d, 3J C‐F =8Hz),128.0,127.6,126.6,126.5,125.0,123.8,121.8,121.22,121.19,120.2,119.9,115.8(d, 2 J C‐F =21Hz),81.7,55.9,54.5,46.1,43.4ppm.

[0096] 19 F NMR (376MHz, CDCl3): δ-115.5ppm.

[0097] Example 11: Synthesis of Chiral Fluorene 3k

[0098] The product was a white solid (24h, 47.1 mg, 95% yield, 88% ee).

[0099] The characterization data are as follows:

[0100] 1 H NMR (400MHz, CDCl3): δ7.95-7.92(m,1H),7.91-7.89(m,1H),7.79-7.71(m,3H),7.64-7.60(m,2H),7.57-7.53(m,2H),7.49-7.45(m,1H),7.40- 7.33(m,3H),7.16-7.11(m,2H),6.61(s,1H),5.07-5.01(m,1H),4.56-4 .49(m,1H),2.75-2.63(m,2H),2.50-2.45(m,1H),2.31-2.25(m,1H)ppm.

[0101] 13 C NMR (100MHz, CDCl3): δ168.0,162.5(d, 1 J C‐F =245Hz),153.0,152.4,152.3,140.1,139.2,138.6,137.5(d, 4 J C‐F =3Hz),135.2,128.8(d, 3 J C‐F =8Hz),127.9,127.6,126.5(two C),125.0,123.2,122.4,121.21,121.17,120.1,120.0,115.7(d, 2 J C‐F=21Hz),81.6,55.7,54.5,46.2,43.2ppm.

[0102] 19 F NMR (376MHz, CDCl3): δ-115.7ppm

[0103] HRMS(ESI+)Calcd for C 30 H 23 FNOS2[M+H] + :496.1200,found:496.1193.

[0104] Example 12: Synthesis of Chiral Fluorene 3l

[0105] The product was a white solid (24h, 51.3 mg, 94% yield, 99% ee).

[0106] The characterization data are as follows:

[0107] 1 H NMR (400MHz, CDCl3): δ7.91–7.89(m,1H),7.84–7.82(m,1H),7.81–7.80(m,1H),7.78–7.70(m,7H),7.61–7.59(m,1H),7.49–7.45(m,1H),7.42- 7.34(m,3H),6.60(s,1H),5.10–5.05(m,1H),4.58–4.52(m,1H),2.79–2 .74(m,1H),2.66–2.60(m,1H),2.48–2.42(m,1H),2.34–2.28(m,1H)ppm.

[0108] 13 C NMR (100MHz, CDCl3): δ168.0,152.8,152.4,152.3,144.8,139.8,139.4,138.7, 135.1,129.3(d, 2 J C-F =32Hz),128.3,127.7,127.5,126.9,126.5,125.8(d, 3 J C-F =4Hz),125.0,124.3(d, 1 J C-F =270Hz),123.9,122.1,121.23,121.17,120.3,120.0,81.8,56.0,54.5,46.0,43.2ppm.

[0109] 19 F NMR (376MHz, CDCl3): δ-62.3ppm.

[0110] HRMS(ESI+)Calcd for C 31 H 23 F3NOS2[M+H] + :546.1168,found:546.1167.

[0111] Example 13: Synthesis of Chiral Fluorene 3m

[0112] The product was a white solid (24h, 45.3 mg, 83% yield, 90% ee).

[0113] The characterization data are as follows:

[0114] 1 H NMR (300MHz, CDCl3): δ8.03(s,1H),7.92–7.90(m,1H),7.77–7.70(m,7H),7.62–7.60(m,2H),7.51–7.46(m,1H),7.39–7.3 4(m,3H),6.57(s,1H),5.07–5.05(m,1H),4.58–4.53(m,1H),2.79–2.62(m,2H),2.52–2.45(m,1H),2.35–2.27(m,1H)ppm.

[0115] 13 C NMR (100MHz, CDCl3): δ168.0,153.2,152.33,152.27,144.9,139.54,139.48,139.0,135.1,129.3(d, 2 J C-F =32Hz),128.2,127.7,127.5,126.8,126.6,125.8(d, 3 J C-F =4Hz),125.0,124.2(q, 1 JC - F=270Hz),123.2,122.7,121.23,121.17,120.3,120.1,81.6,55.9,54.5,46.1,43.2ppm.

[0116] 19 F NMR (376MHz, CDCl3): δ-62.3ppm

[0117] HRMS(ESI+)Calcd for C 31 H 23 F3NOS2[M+H] + :546.1168,found:546.1173.

[0118] Example 14: Synthesis of Chiral Fluorene 3n

[0119] The product was a white solid (24h, 44.3 mg, 84% yield, 94% ee).

[0120] The characterization data are as follows:

[0121] 1 H NMR (300MHz, DMSO): δ8.31(s,1H),8.13(s,1H),8.05–8.03(m,2H),7.98-7.85(m,6H),7.81–7.79(m,2H),7.60–7.52(m,2H),7.45– 7.40(m,2H),7.33–7.31(m,2H),5.83–5.82(m,1H),4.89–4.85(m,1H),4.51–4.43(m,1H),2.73–2.59(m,3H),2.22–2.16(m,1H)ppm.

[0122] 13 C NMR (100MHz, DMSO‐d6): δ166.5,154.5,154.1,153.2,140.4,138.80,138.75,138.3,135.0,133.9,132.7,128.9,128.7,128.6,128.0, 127.8,126.9,126.83,126.76,126.6,125.9,125.8,125.0,124.3,122.6,122.2,121.6,120.8,120.4,76.6,55.2,54.9,46.4,44.8ppm.

[0123] HRMS(ESI+)Calcd for C 34 H 26 NOS2[M+H] + :528.1450,found:528.1449.

[0124] Example 15: Synthesis of Chiral Fluorene 3o

[0125] The product was a white solid (24 h, 50.1 mg, 95% yield, 85% ee).

[0126] The characterization data are as follows:

[0127] 1 H NMR (400MHz, CDCl3): δ8.12-8.11(m,2H),7.94–7.89(m,3H),7.87–7.85(m,1H),7.84–7.72(m,5H),7.60–7.58(m, 1H),7.52–7.44(m,3H),7.41–7.33(m,3H),6.67(s,1H),5.10–5.04(m,1H),4.60–4.54(m,1H),2.77–2.71(m,1H), 2.58–2.52(m,2H),2.33–2.27(m,1H)ppm.

[0128] 13 C NMR (100MHz, CDCl3): δ168.0,153.0,152.6,152.3,141.0,139.2,138.7,135.2,133.7,132.7,128.5,128.3(two C),127.9,127.7,127.6,127.0,126.5,126.4,126.0,125.8,125.7,125.0,123.2,122.6,121.2(two C),120.2,120.0,81.6,55.7,54.4,46.4,43.1ppm.

[0129] HRMS(ESI+)Calcd for C 34 H 26 NOS2[M+H] + :528.1450,found:528.1450.

[0130] Example 16: Synthesis of Chiral Fluorene 3p

[0131] The product was a white solid (24h, 40.7 mg, 87% yield, 94% ee).

[0132] The characterization data are as follows:

[0133] 1H NMR (400MHz, CDCl3): δ7.85-7.83(m,1H),7.76-7.70(m,3H),7.64-7.58(m,3H),7.42-7.38(m,2H),7.31-7.26(m,3H),6.64-6.63(m,1 H),6.52(s,1H),6.43-6.42(m,1H),5.02-4.96(m,1H),4.50-4.43(m,1H),2.73-2.68(m,1H),2.51-2.45(m,1H),2.36-2.22(m,2H)ppm.

[0134] 13 C NMR (100MHz, CDCl3): δ168.1,154.2,152.5,152.4,152.3,142.1,139.0,138.9,135.2,130.5,127.9,127.5,12 6.5,124.9,123.9,123.4,121.21,121.19,120.1,119.8,118.4,111.9,105.1,81.7,55.8,54.6,46.0,43.3ppm.

[0135] HRMS(ESI+)Calcd for C 28 H 22 NO2S2[M+H] + :468.1086,found:468.1081.

[0136] Example 17: Synthesis of Chiral Fluorene 3q

[0137] The product was a white solid (24h, 37.9 mg, 81% yield, 87% ee).

[0138] The characterization data are as follows:

[0139] 1H NMR (400MHz, CDCl3): δ8.05(s,1H),7.94-7.92(m,1H),7.80-7.78(s,1H),7. 71-7.67(m,3H),7.57-7.55(m,1H),7.50-7.46(m,2H),7.38-7.32(m,3H),6. 72-6.71(m,1H),6.49-6.48(m,1H),6.49-6.48(m,1H),5.07-5.02(m,1H),4. 57-4.51(m,1H),2.73-2.65(m,2H),2.52-2.46(m,1H),2.29-2.23(m,1H)ppm.

[0140] 13 C NMR (100MHz, CDCl3): δ168.0,154.2,152.8,152.6,152.3,142.1,139.2,138.6,135.2,130.6,127.9,127.6,12 6.5,124.9,123.4,123.2,121.21,121.20,120.1,119.8,118.9,111.8,105.1,81.6,55.5,54.4,46.3,42.9ppm.

[0141] HRMS(ESI+)Calcd for C 28 H 22 NO2S2[M+H] + :468.1086,found:468.1089.

[0142] Example 18: Synthesis of Chiral Fluorene 3r

[0143] The product was a white solid (24h, 43.6 mg, 88% yield, 94% ee).

[0144] The characterization data are as follows:

[0145] 1H NMR (400MHz, CDCl3): δ7.91-7.89(m,1H),7.84-7.82(m,1H),7.78-7.71(m,4H),7.57-7.44(m,3H),7.40-7.31( m,4H),7.25-7.16(m,2H),6.58(s,1H),5.06-5.01(m,1H),4.57-4.50(m,1H),2.81-2.75(m,1H),2.61-2.56(m, 1H),2.45-2.40(m,1H),2.36-2.30(m,1H)ppm.

[0146] 13 C NMR (100MHz, CDCl3): δ168.1,159.8(d, 1 J C-F =246Hz),152.6,152.2(d, 2 J C-F =24Hz),139.1(d, 2 J C-F =25Hz),135.4,135.2,130.8(d, 4 J C-F =3Hz),129.2(d, 3 J C-F =13Hz),129.0(d, 3 J C-F =8Hz),128.5(d, 4 J C-F =3Hz),128.1,127.5,126.5,124.9,124.50,124.46,123.9,123.81,123.78,121.19,121.17,119.8(d, 3 J C-F =13Hz),116.3,116.1,81.7,55.9,54.5,46.0,43.3ppm.

[0147] HRMS(ESI+)Calcd for C 30 H 23 FNOS2[M+H] + :496.1200,found:496.1196.

[0148] Example 19: Synthesis of Chiral Fluorene 3s

[0149] The product was a white solid (24h, 61.1 mg, 93% yield, 93% ee).

[0150] The characterization data are as follows:

[0151] 1 H NMR (400MHz, CDCl3): δ8.11-8.09(m,1H),7.97-7.95(m,2H),7.91-7.83(m,3H),7.80-7.72(m,5H),7.63-7.61(m,1H),7.56-7.52(m,1H),7.48- 7.32(m,8H),6.59(s,1H),5.09-5.04(m,1H),4.60-4.53(m,1H),2.81-2 .75(m,1H),2.67-2.62(m,1H),2.49-2.43(m,1H),2.36-2.30(m,1H)ppm.

[0152] 13 C NMR (100MHz, CDCl3): δ168.0,152.6,152.3,152.3,139.2,139.0,138.2,135.6,135.1,134.0,132.5,129.4,129.3,128.1,127.6,127.4,12 6.9,126.5,125.1,124.9,124.4,123.9,123.8,123.0,122.6,121.22, 121.16,120.6,120.3,119.9,113.9,81.7,56.0,54.5,46.1,43.3ppm.

[0153] HRMS(ESI+)Calcd for C 32 H 29 NOS2[M+H] + :657.1335,found:657.1329.

[0154] Example 20: Synthesis of Chiral Fluorene 3t

[0155] The product was a white solid (24h, 38.0 mg, 72% yield, 94% ee).

[0156] The characterization data are as follows:

[0157] 1H NMR (400MHz, DMSO-d6): δ7.91-7.87(m,3H),7.81-7.67(m,4H),7.48-7.44(m,1H),7.37-7.33(m,3H),6.07(s,1H) ,4.98-4.93(m,1H),4.56-4.49(m,1H),2.81-2.75(m,1H),2.43-2.36(m,2H),2.26-2.21(m,1H),1.33(s,12H)ppm.

[0158] 13 C NMR (100MHz, DMSO-d6): δ168.3,152.2,152.4,150.6,142.6,139.0,135.2,134.1,128.9,128.3,127.4,126.4,124.8,124.2,121.3,121.0 (two C),120.1,119.1,83.9,81.5,55.8,54.9,45.6,43.5,24.7ppm.

[0159] HRMS(ESI+)Calcd for C 30 H 31 BNO3S2[M+H] + :528.1833,found:528.1838.

[0160] Example 21: Synthesis of Chiral Fluorene 3u

[0161] The product was a white solid (24h, 53.2 mg, 95% yield, 93% ee).

[0162] The characterization data are as follows:

[0163] 1 H NMR (300MHz, CDCl3): δ7.83-7.80(m,1H),7.78-7.69(m,8H),7.59-7.55(m,2H),7.41-7.37(m,2H),7.27-7.24(m, 1H),6.68(s,1H),5.10-5.02(m,1H),4.55-4.46(m,1H),2.78-2.71(m,1H),2.64-2.57(m,1H),2.46-2.40(m,4H), 2.33-2.25(m,1H)ppm.

[0164] 13C NMR (75MHz, CDCl3): δ166.5,152.8,152.5,150.4,144.8,139.8,139.4,138.7,135.3,135.2,129.3(q, 2 J C-F =43Hz),128.3,128.0,127.6,127.5,126.9,125.8(q, 3 J C-F =5Hz),124.4(q, 1 J C-F =260Hz),123.9,122.1,121.0,120.7,120.3,120.0,81.7,55.9,54.4,46.1,43.2,21.5ppm.

[0165] 19 F NMR (282MHz, CDCl3): δ-62.3ppm.

[0166] HRMS(ESI+)Calcd for C 32 H 25 F3NOS2[M+H] + :560.1324,found:560.1314.

[0167] Example 22: Synthesis of Chiral Fluorene 3v

[0168] The product was a white solid (24h, 54.7 mg, 95% yield, 92% ee).

[0169] The characterization data are as follows:

[0170] 1 H NMR (400MHz, CDCl3): δ7.83-7.81(m,1H),7.78-7.70(m,7H),7.61-7.57(m,2H),7.41-7.38(m,3H),7.00-6.97(m,1H),6.74(s,1H), 5.09-5.03(m,1H),4.55-4.49(m,1H),3.86(s,3H),2.79-2.74(m,1H),2.63-2.57(m,1H),2.47-2.41(m,1H),2.33-2.27(m,1H)ppm.

[0171] 13C NMR (100MHz, CDCl3): δ168.8,159.3,153.5,152.8,152.5,144.8,139.8,139.4,138.7,129.3(q, 2 J C-F =32Hz),128.3,127.7,127.5,126.9,126.7,125.8(q, 3 J C-F =4Hz),124.4(q, 1 J C-F =270Hz),123.9,122.0,121.4,120.3,120.1,114.9,104.0,81.8,55.9,55.7,54.5,46.1,43.2ppm.

[0172] 19 F NMR (376MHz, CDCl3): δ-62.3ppm.

[0173] HRMS(ESI+)Calcd for C 32 H 25 F3NO2S2[M+H] + :576.1273,found:576.1267.

[0174] Example 23: Synthesis of Chiral Fluorene 3w

[0175] The product was a white solid (24h, 46.3 mg, 74% yield, 96% ee).

[0176] The characterization data are as follows:

[0177] 1 H NMR (400MHz, CDCl3): δ8.06-8.04(m,1H),7.84-7.82(m,1H),7.78-7.70(m,7H),7.72-7.57(m,2H),7.56-7.44(m,1H),7.40-7.37(2H) ),6.15(s,1H),5.07-5.01(m,1H),4.57-4.50(m,1H),2.79-2.74(m,1H),2.64-2.58(m,1H),2.45-2.40(m,1H),2.34-2.28(m,1H)ppm.

[0178] 13C NMR (100MHz, CDCl3): δ170.0,153.4,152.6,152.4,144.8,139.9,139.4,138.7,133.9,129.3(q, 2 JC - F=32Hz),128.3,128.0,127.7,127.5,126.9,125.8(q, 3 JC - F=4Hz),124.3(q, 1 JC - F=270Hz),124.1,123.9,122.2,122.0,120.4,120.2,120.1,81.6,56.0,54.7,45.9,43.3ppm.

[0179] 19 F NMR (376MHz, CDCl3): δ-62.3ppm.

[0180] HRMS(ESI+)Calcd for C 31 H 22 BrF3NOS2[M+H] + :624.0273,found:624.0268.

[0181] Example 24: Synthesis of Chiral Fluorene 3x

[0182] The product was a white solid (24h, 58.3 mg, 95% yield, 88% ee).

[0183] The characterization data are as follows:

[0184] 1 H NMR (400MHz, CDCl3): δ8.19(s,1H),7.91-7.85(m,2H),7.81-7.71(m, 7H),7.62-7.60(m,2H),7.43-7.39(m,2H),6.10(s,1H),5.10-5.05(m,1H),4.63-4.57( m,1H),2.83-2.78(m,1H),2.67-2.61(m,1H),2.48-2.43(m,1H),2.38-2.32(m,1H)ppm.

[0185] 13C NMR (100MHz, CDCl3): δ170.7,152.5,152.3,152.0,144.8,139.9,139.4,138.7,138.6,129.4(q, 2 JC - F=32Hz),129.3(q, 2 JC - F=32Hz),128.3,127.7,127.4,127.0,125.8(q, 3 JC - F=4Hz),124.33(q, 1 JC - F=270Hz),124.0(q, 1 JC - F=270Hz),123.9,122.0,121.8,121.4(q, 3 JC - F=4Hz),120.4,120.1,118.3(q, 3 JC-F=4Hz),81.6,56.0,54.8,45.9,43.4ppm.

[0186] 19 F NMR (376MHz, CDCl3): δ-61.8,-62.3ppm.

[0187] HRMS(ESI+)Calcd for C 32 H 22 F6NOS2[M+H] + :614.1047,found:614.1044.

[0188] Example 25: Synthesis of Chiral Fluorene 3y

[0189] The product was a green solid (24h, 54.9 mg, 95% yield, 83% ee).

[0190] The characterization data are as follows:

[0191] 1H NMR (400MHz, CDCl3): δ8.53(s,1H),8.10-8.06(m,2H),7.94-7.91(m,2H),7 .86-7.77(m,4H),7.72-7.70(m,1H),7.65-7.63(m,1H),7.53-7.37(m,8H), 7.33-7.30(m,1H),6.53(s,1H),4.93-4.88(m,1H),4.57-4.50(m,1H),2.86 -2.83(m,1H),2.67-2.61(m,1H),2.53-2.48(m,1H),2.41-2.35(m,1H),ppm.

[0192] 13 C NMR (100MHz, CDCl3): δ168.0,152.8,152.23,152.18,139.4,139.0,138.5, 137.1,135.1,131.5,131.4,130.7,130.4,130.3,128.51,128.46,128.1,127.6,126.9,126.85,126.78,126.4,12 6.0,125.7,125.5,125.23,125.17,124.8,124.0,121.14,121.11,119.9,119.8,81.5,55.9,54.6,46.1,43.5ppm.

[0193] HRMS(ESI+)Calcd for C 38 H 28 NOS2[M+H] + :578.1612,found:578.1603.

[0194] Example 26: Synthesis of Chiral Fluorene 3z

[0195] The product was a white solid (24h, 46.2 mg, 80% yield, 95% ee).

[0196] The characterization data are as follows:

[0197] 1H NMR (400MHz, CDCl3): δ8.82-8.80(m,1H),8.76-8.74(m,1H),8.05-8.03(m,1H),7 .96-7.94(m,1H),7.90-7.85(m,3H),7.82-7.79(m,2H),7.75-7.57(m,7H),7.46- 7.40(m,3H),7.34-7.30(m,1H),6.56(s,1H),5.04-4.98(m,1H),4.59-4.52(m,1H ),2.89-2.83(m,1H),2.67-2.62(m,1H),2.53-2.48(m,1H),2.42-2.36(m,1H)ppm.

[0198] 13 C NMR (100MHz, CDCl3): δ166.9,151.5,151.1,151.0,139.4,138.0,137.9,137.8,134.0,130.5,130.1,129.7,128.9,128.5(two C),127.7,126.9,126.6,126.5,125.9,125.6(two C),125.4,125.3,123.74,123.67,122.8,121.9,121.5,120.04,120.01,118.8,118.6,80.5,54.8,53.5,44.9,42.3ppm.

[0199] HRMS(ESI+)Calcd for C 38 H 28 NOS2[M+H] + :578.1612,found:578.1607.

[0200] Example 27: Synthesis of Chiral Fluorene 3za

[0201] The product was a white solid (24h, 41.2 mg, 91% yield, 99% ee).

[0202] The characterization data are as follows:

[0203] 1H NMR (400MHz, CDCl3): δ8.30-8.25(m,2H),8.22-8.18(m,2H),8.11-8.01(m,5H),7.91-7.81(m,5H),7.72-7.65(m,2H),7.47-7.38(m,3H),7.3 2-7.28(m,1H),6.57(s,1H),5.05(m,1H),4.59-4.52(m,1H),2.90-2.8 5(m,1H),2.71-2.65(m,1H),2.55-2.50(m,1H),2.44-2.37(m,1H)ppm.

[0204] 13 C NMR (100MHz, CDCl3): δ168.0,152.6,152.23,152.19,140.9,139.1,138.8,137 .8,135.1,131.5,131.0,130.7,130.2,128.6,128.1,127.8,127.7,127.6,127 .52,127.48,126.4,126.1,125.4,125.3,125.2,125.1,125.0,124.9,124.83, 124.77,123.9,121.14,121.11,120.0,119.8,81.6,56.0,54.5,46.1,43.4ppm.

[0205] HRMS(ESI+)Calcd for C 40 H 28 NOS2[M+H] + :602.1607,found:602.1607.

[0206] Example 28: Synthesis of Chiral Fluorene 3zb

[0207] The product was a green solid (24h, 65.7 mg, 90% yield, 92% ee).

[0208] The characterization data are as follows:

[0209] 1H NMR (400MHz, CDCl3): δ7.97-7.96(m,1H),7.84-7.92(m,1H),7.80-7.78(m ,1H),7.74-7.72(m,2H),7.59-7.57(m,2H),7.50-7.46(m,3H),7.39-7.35 (m,3H),7.17‐7.06(m,17H),5.09‐5.04(m,1H),4.57‐4.51(m,1H),2.74‐2.66(m,2H),2.53‐2.48(m,1H),2.31‐2.25(m,1H)ppm.(‐OH is not shown).

[0210] 13 C NMR (100MHz, CDCl3): δ168.0,152.9,152.6,152.3,143.9(two C),143.80,143.79,142.9,141.2,140.6,139.3,139.0,138.5,135.2,132.0,131.5(two C),131.4,127.9(two C),127.8,127.7,127.6,126.6,126.5(two C),126.47,126.4,126.3,125.0,123.2,122.0,121.3,121.2,120.0,119.9,81.6,55.6,54.4,46.4,43.0ppm.

[0211] HRMS(ESI+)Calcd for C 50 H 38 NOS2[M+H] + :732.2389,found:732.2384.

[0212] Example 29: Synthesis of Chiral Fluorene 3zc

[0213] The product was a white solid (24h, 48.0 mg, 95% yield, 94% ee).

[0214] The characterization data are as follows:

[0215] 1H NMR (300MHz, CDCl3): δ7.91–7.88(m,1H),7.79–7.74(m,4H),7.60–7.57( m,1H),7.49–7.42(m,1H),7.40–7.33(m,4H),7.27–7.24(m,1H),7.14–7.0 9(m,2H),6.54(s,1H),5.08–5.00(m,1H),4.53–4.45(m,1H),2.79–2.66(m ,2H),2.52–2.45(m,1H),2.39(s,3H),2.36(s,3H),2.31–2.27(m,1H)ppm.

[0216] 13 C NMR (100MHz, CDCl3): δ166.9,151.24,151.19,151.17,140.6,138.4,138.1,136.8,135.9,134.2,134.1,130.2,128.8,127.6, 126.7,126.5,125.5,125.4,123.8,123.6,122.0,120.14,120.08,118.7,118.3,80.5,54.6,53.3,45.2,42.0,20.0,19.6ppm.

[0217] HRMS(ESI+)Calcd for C 32 H 28 NOS2[M+H] + :506.1607,found:506.1608.

[0218] Example 30: Synthesis of Chiral Fluorene 3zd

[0219] The product was a white solid (24h, 48.2 mg, 95% yield, 91% ee).

[0220] The characterization data are as follows:

[0221] 1H NMR (400MHz, CDCl3): δ7.93-7.92(m,1H),7.90-7.88(m,1H),7.78-7.71(m,3H),7.59-7.56(m,2H),7.48-7.44(m,1H),7.39-7.33(m,3H),7.29(s ,2H),7.00(s,1H),6.68(s,1H),5.08-5.02(m,1H),4.57-4.50(m,1H),2 .75-2.66(m,2H),2.55-2.49(m,1H),2.39(s,6H),2.29-2.23(m,1H)ppm.

[0222] 13 C NMR (100MHz, CDCl3): δ168.1,152.8,152.7,152.3,141.42,141.39,139.3,138.5,138.4,135.2,129.0,127.8,127. 5,126.7,126.5,125.2,124.9,123.2,122.4,121.21,121.15,120.0,119.9,81.6,55.5,54.3,46.5,42.9,21.5ppm.

[0223] HRMS(ESI+)Calcd for C 32 H 28 NOS2[M+H] + :506.1607,found:506.1605.

[0224] Example 31: Synthesis of Chiral Fluorene 3ze

[0225] The product was a white solid (24h, 39.6 mg, 95% yield, 99% ee).

[0226] The characterization data are as follows:

[0227] 1 H NMR (300MHz, DMSO): δ9.64(s,1H),8.02–7.88(m,2H),7.60–7.28(m,8H),6.79(s,1H),5.80(s,1H),4.70(s,1H),4.39(s,1H),2.70-2.12(m,4H)ppm.

[0228] 13C NMR (75MHz, DMSO): δ166.4,158.5,156.0,153.2,152.9,139.7,135.1,130.3,127.6 ,126.9,126.8,125.1,123.5,122.2,121.7,121.1,119.0,114.8,111.4,76.8,55.0, 54.6,46.8,45.0ppm.

[0229] HRMS(ESI+)Calcd for C 24 H 20 NO2S2[M+H] + :418.0930,found:418.0927.

[0230] Example 32: Synthesis of Chiral Fluorene 3zf

[0231] The product was a red solid (24h, 68.7 mg, 95% yield, 88% ee).

[0232] The characterization data are as follows:

[0233] 1 H NMR (400MHz, CDCl3): δ8.08(s,1H),7.90-7.67(m,7H),7.60-7.57(m,1H),7.48-7.34(m,6H),5.98(s,2H),5.10-5.0 3(m,1H),4.61-4.53(m,1H),2.78-2.68(m,2H),2.57(s,6H),2.52-2.48(m,1H),2.34-2.26(m,1H),1.46(s,6H)ppm.

[0234] 13 C NMR (100MHz, CDCl3): δ168.0,155.5,153.2,152.7,152.3,143.2,141.7,141.6,139.6,139.2,139.0,135.2,133.9,131.5,129.5,128.6 ,128.2,127.7,127.6,126.59,126.57,125.0,123.2,122.2,121.3,121.1,120.3,120.1,81.5,55.7,54.4,46.4,43.0,14.74,14.66ppm.

[0235] 19F NMR (376MHz, CDCl3): δ-146.0 (d, J = 32Hz), -146.2 (d, J = 32Hz) ppm.

[0236] HRMS(ESI+)Calcd for C 43 H 37 BF2N3OS2[M+H] + :724.2434,found:724.2428.

[0237] Example 33: Synthesis of Chiral Fluorene 3zg

[0238] The product was a green solid (24 h, 58.2 mg, 95% yield, 90% ee).

[0239] The characterization data are as follows:

[0240] 1 H NMR (300MHz, CDCl3): δ8.43(s,1H),8.00–7.95(m,2H),7.81–7.74(m,3H),7.67–7.62(m,4H),7.52(s,1H),7.51–7.35(m,4H) ,7.52–7.16(m,4H),4.81–4.74(m,1H),4.42–4.34(m,1H),2.77–2.70(m,1H),2.56–2.49(m,1H),2.39–2.22(m,2H)ppm.(-OH is not shown)

[0241] 13 C NMR (75MHz, CDCl3): δ167.7,154.5,152.2,152.0,138.8,138.0,137.8,136.8,135.1,133.6,131.4,130.9,130.32,130.27,128.5,128.4,127.9 ,126.8,126.7,126.6,126.4,126.0,125.7,125.6,125.21,125.15,124 .9,124.6,121.2,121.1,120.8,119.8,81.3,56.1,54.5,45.8,43.4ppm.

[0242] HRMS(ESI+)Calcd for C 38 H 27 ClNOS2[M+H] + :612.1217,found:612.1219.

[0243] Example 33: Synthesis of Chiral Fluorene 3zh

[0244] The product was a green solid (24 h, 58.2 mg, 95% yield, 87% ee).

[0245] The characterization data are as follows:

[0246] 1 H NMR (300MHz, CDCl3): δ8.42(s,1H),8.00–7.95(m,2H),7.80–7.77(m,1H),7.70(s,1H),7.67–7.62(m,5H),7.51(s,1H),7.41–7.26 (m,7H),7.23–7.20(m,1H),4.92–4.84(m,1H),4.27–4.18(m,1H),2.70–2.62(m,2H),2.47–2.39(m,1H),2.29–2.21(m,1H)ppm(the proton of OH is not displayed).

[0247] 13 C NMR (100MHz, CDCl3): δ167.4,154.6,152.7,152.1,139.0,137.9,137.6,136.9, 136.72,136.6,135.1,133.6,131.4,131.3,130.8,130.34,130.29,128.5,128.4,127.9,126.8,126.7,126 .4,125.7,125.5,125.2,125.1,124.9,123.8,121.3,121.0,120.9,119.7,81.1,55.5,54.1,46.6,42.7ppm.

[0248] HRMS(ESI+)Calcd for C 38 H 27 ClNOS2[M+H] + :612.1217,found:612.1208.

[0249] Example 34: Synthesis of Chiral Silaspirofluorene 3zi

[0250] The product was a white solid (24h, 38.9 mg, 90% yield, 81% ee).

[0251] The characterization data are as follows:

[0252] 1 H NMR (600MHz, CDCl3) δ7.97–7.95(m,1H),7.81–7.73(m,4H),7.54–7.47(m,3H),7.39–7.36(m,1H),7.33–7. 27(m,2H),4.66–4.62(m,1H),4.32–4.28(m,1H),2.44(s,3H),1.88–1.84(m,2H),1.45–1.36(m,2H)ppm(the proton of OH is not displayed).

[0253] 13 CNMR (150MHz, CDCl3) δ167.6,152.1,148.5,145.8,137.7,135.1,134.7,134.5,134.1,133.5,1 31.9,131.1,127.5,126.5,125.0,121.4,121.1,120.9,120.7,78.8,55.1,21.3,20.0,15.9ppm.

[0254] HRMS(ESI+)Calcd for C 24 H 22 NOS2Si[M+H] + :432.0912,found:432.0901.

[0255] Example 35: Synthesis of Chiral Silaspirofluorene 3zj

[0256] The product was a white solid (24h, 38.0 mg, 88% yield, 78% ee).

[0257] The characterization data are as follows:

[0258] 1 H NMR (600MHz, CDCl3) δ7.94(d,J=6.0Hz,1H),7.80(d,J=6.0Hz,2H),7.75–7.73(m,2H),7.58(s,1H),7.50–7.47(m,2H),7.38– 7.36(m,1H),7.34–7.28(m,2H),4.67–4.63(m,1H),4.32–4.28(m,1H),2.42(s,3H),1.88–1.84(m,2H),1.44–1.36(m,2H)ppm.

[0259] 13 CNMR (150MHz, CDCl3) δ167.2,152.5,148.6,145.8,137.7,135.4,134.8,134.4,134.2,133.4,1 31.9,131.1,127.5,126.4,124.8,121.5,121.1,120.8,120.7,78.7,55.0,21.3,20.1,16.0ppm.

[0260] HRMS(ESI+)Calcd for C 24 H 22 NOS2Si[M+H] + :432.0912,found:432.0902.

[0261] Other embodiments:

[0262] The influence of other reaction conditions on the reaction:

[0263] a Initial reaction conditions: Epoxide 1a (0.05 mmol), mercaptobenzothiazole 2a (0.055 mmol), and chiral phosphoric acid catalyst C1 (5.0 mg, 10 mol%) were placed in 0.5 mL of xylene and reacted at 25°C for 10 hours. b The NMR yield was determined using dibromomethane as the internal standard. c Chiral high performance liquid chromatography determination. d 24-hour response time. e 72 hours response time. f The numbers in brackets are the isolated yields.

[0264] From the above table, it can be seen that when the catalyst side chain benzene ring 2, 6 contains isopropyl substitution, the stereoselectivity is best controlled. In addition, reducing the amount of catalyst to 0.1 mol% has no effect on the reaction.

[0265] The spectral properties and aggregation-induced emission properties of the compounds were further studied. The following selected compounds are only representative, and it can be expected that other similar compounds will also have similar properties.

[0266] Spectral property study: Determination of fluorescence quantum yield by integrating sphere method: (conventional instrument measurement)

[0267] Example a: 3y (10 μM dichloromethane solution):

[0268] Example b: 3za (10 μM dichloromethane solution):

[0269] Example c: 3zb (10 μM water / tetrahydrofuran mixed solution (volume ratio = 99:1)):

[0270] Example d: 3zf (10 μM dichloromethane solution):

[0271] The conclusion drawn from Figures 1-4 is that the above compounds all have good fluorescence quantum yields.

[0272] Aggregation-induced emission:

[0273] Example e: 3zb aggregation-induced emission:

[0274] 3zb (10 μM) was dissolved in different ratios of tetrahydrofuran / water mixed solvents, and its fluorescence spectra were measured. The results were as follows: with the increase of the content of poor solvent water, the aggregation-induced emission gradually increased and reached a fluorescence quantum yield of 31.2%.

[0275] From the above table, we can see that 3zb has very good aggregation-induced emission performance (Figure 5-6). Energy level test:

[0276] Example f: 3za energy level test

[0277] Test conditions: nitrogen protection;

[0278] Electrochemical workstation: CS350H (Wuhan CorrTest Co., Ltd).

[0279] Counter electrode: platinum electrode;

[0280] IUPAC drawing rules;

[0281] Working electrode: Glassy carbon electrode (GCE, φ = 3 mm) was carefully polished with sandpaper and then sonicated in acetone;

[0282] Reference electrode (Ag / Ag + ), electrolyte: 9.8mg AgNO3in 5.8mL CH3CN (0.01mol / L);

[0283] Electrolytic cell: 30mL.

[0284] Ferrocene as internal standard: 20 mg ferrocene, and 720 mg n-Bu4NPF6 in 20 mL DCM;

[0285] Electrochemical workstation test parameters: High E = 1 V; Low = -0.5 V; Scan Rate = 100 mV / s; Segment = 4; Smpl interval = 0.001 V; Quiet Time = 4 s, Sensitivity = 1 e -4 A / V.3za: 8mg 3za, and 720mg n-Bu4NPF6in 20mL DCM;

[0286] Electrochemical workstation test parameters: High E = 3V; Low = 0V; Scan Rate = 100mV / s; Segment = 4; Smpl interval = 0.001V; Quiet Time = 4s, Sensitivity = 1e -4 A / V

[0287] Energy level test results:

[0288] HOMO=-(1.075+4.8-0.182)=-5.693eV

[0289] E g =3.05eV

[0290] LUMO=-(5.693-3.05)=-2.643eV

[0291] The results indicate that 3za can be used as a potential electron transport material for OLEDs.

Claims

1. A method for preparing a chiral fluorene containing a 9-position quaternary carbon stereocenter, characterized in that: Under the catalysis of chiral phosphoric acid, mercaptobenzothiazole nucleophile 2 was used in organic solvent to perform ring-opening desymmetrization on fluorene-derived prochiral epoxide 1 to generate chiral spirofluorene 3 with discontinuous chiral centers. Among them, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 are independently selected from one or more combinations of alkyl or perfluoroalkyl, substituted alkyl, alkoxy, substituted alkoxy, alkylthio, substituted alkylthio, aryl, substituted aryl, heteroaryl, substituted heteroaryl, halogen, hydroxyl, alkenyl, alkynyl, nitro, borate, amino, aminoalkoxycarbonyl and hydrogen; X is one of S, N, and O; A is one of carbon and silicon.

2. The method for preparing a chiral fluorene containing a 9-quaternary carbon stereocenter according to claim 1, characterized in that: The R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each independently selected from C1-C 20 Alkyl, substituted C1-C 20 Alkyl, C1-C 20 Alkoxy, substituted C1-C 20 Alkoxy, C1-C 20 Alkylthio, substituted C1-C 20 Alkylthio, C6-C 20 Aryl, substituted C6-C 20 Aryl, C4-C 20 Heteroaryl, substituted C4-C 20 Heteroaryl, C1-C 20 Substituted alkenyl, C1-C 20 Substituted alkynyl, C1-C 20 At least one of a substituted aminoalkoxycarbonyl group, a borate group, a hydroxyl group, an amino group, a nitro group, a halogen group and a hydrogen group.

3. The method for preparing a chiral fluorene containing a 9-quaternary carbon stereocenter according to claim 2, characterized in that: The R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 Each independently selected from C1-C 10 Alkyl, C6-C 16 C6-C 16 Aryl, C4-C 20 Heteroaryl, substituted C4-C 20 At least one of heteroaryl, halogen and hydrogen.

4. The method for preparing a chiral fluorene containing a 9-quaternary carbon stereocenter according to claim 2, characterized in that: The substituents in the substituted alkyl, substituted alkoxy, substituted alkylthio, substituted aryl, and substituted heteroaryl are selected from halogen, N-dimethylamino, C1-C4 alkyl, halogen-substituted C1-C4 alkyl, C3-C6 cycloalkyl, halogen-substituted C3-C6 cycloalkyl, C1-C4 alkoxy, halogen-substituted C1-C4 alkoxy, methylenedioxy, C6-C 16 Aryl, C6-C1-C5 alkyl-substituted 16 Aryl, C6-C 16 At least one of an aryloxy group, a cyano group, a nitro group, a hydroxyl group, an amino group, and a carboxyl group.

5. The method for preparing a chiral fluorene containing a 9-quaternary carbon stereocenter according to claim 2, characterized in that: The chiral phosphoric acid catalyst structures are the following three or their corresponding enantiomers: Wherein R=one of 2,4,6-triisopropylphenyl, 2,4,6-tricyclohexylphenyl, 2,6-diisopropyl-4-(1-adamantyl)phenyl, 2,6-diisopropyl-4-(9-anthryl)phenyl and 3,5-diisopropylphenyl.

6. The method for preparing chiral fluorene containing a 9-position quaternary carbon stereocenter according to claim 1, characterized in that: The molar ratio of the mercaptobenzothiazole nucleophile to the epoxy compound electrophile is 1-1.1:

1.

7. The method for preparing a chiral fluorene containing a 9-quaternary carbon stereocenter according to claim 1, characterized in that: The reaction temperature ranges from 0 to -30 °C, and the amount of the chiral phosphoric acid catalyst used is 0.1 to 10 mol%.

8. The method for preparing a chiral fluorene containing a 9-position quaternary carbon stereocenter according to claim 1, characterized in that: The reaction solvent is one of xylene, toluene, dichloromethane, chloroform and ethyl acetate.

9. A chiral fluorene containing a 9-position quaternary carbon stereocenter prepared according to the method of any one of claims 1 to 8, characterized in that: The structural formula of the 9-quaternary carbon stereocenter chiral fluorene is: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 As defined in claim 1 chiral spirofluorene 3; X is one of S, N, and O; A is one of carbon and silicon.

10. The use of chiral fluorene containing a 9-position quaternary carbon stereocenter according to claim 9, characterized in that: Application of chiral fluorene containing 9-position quaternary carbon stereocenter in OLED electron transport materials, fluorescent probes and fluorescent dyes.

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