Method for realizing carbon chain extension of terminal alcohol by two-step method

Abstract

The invention relates to a method for obtaining a compound with a prolonged carbon chain by breaking a carbon-oxygen bond by a terminal alcohol through a two-step method and then generating a carbon-carbon bond. The method comprises the following steps: 1, reacting terminal alcohol (R-OH) with metal salt (MX) of halogen elements to obtain a terminal halogenated compound (R-X); and 2, dehalogenating the terminal halogenated compound to generate a carbon-carbon bond, so as to obtain a compound of which the carbon chain number is twice that of the original terminal alcohol carbon chain number. According to the method, the carbon chain extension reaction of the hydroxyl-containing compound can be realized without a high temperature of 200 DEG C or above or a strong oxidation reducing agent, so that the safety of the process is ensured.

Description

Technical Field

[0001] The invention relates to a two-step method for extending the carbon chain of a terminal alcohol, and specifically to a method of first halogenating the terminal alcohol, then dehalogenating the halogenated compound to generate a carbon-carbon bond, and obtaining a compound with an extended carbon chain. Background Art

[0002] The preparation of fuels and chemicals from small molecule platform compounds produced from renewable biomass resources is one of the important ways to achieve sustainable development. Compared with the traditional energy chemical process based on petroleum as raw materials, biomass-based raw materials have two obvious characteristics: one is the high oxygen content, and the other is the low carbon number of biomass platform compounds. In view of these two characteristics, biomass-based raw materials need to go through the two processes of deoxygenation and chain growth to achieve the purpose of partially replacing petroleum-based chemical raw materials.

[0003] Taking polyol compounds as an example, the most common deoxygenation processes are hydrodeoxygenation and dehydration reactions. However, whether it is hydrodeoxygenation (CN115501898A) or dehydration (CN115322068A), it needs to be carried out above 150°C, wherein hydrodeoxygenation also requires the use of flammable and explosive hydrogen, and is carried out under a certain pressure. In addition, saturated hydrocarbon compounds are usually obtained after hydrodeoxygenation, and it is difficult to continue to achieve the reaction of carbon chain extension. Regarding the chain growth reaction of alcohol compounds, the most representative process is alcohol oxidative dehydrogenation or anaerobic dehydrogenation to generate aldehydes and ketones, and then aldol condensation reaction occurs to obtain carbon chain extension products (CN114130399A, CN108821957A), and the reaction is usually carried out above 200°C. When the carbon number of the alcohol is greater than 2, the carbon chain extension product obtained by this method will contain side chains, which will affect the subsequent application as a surfactant raw material and as a polymer monomer. Therefore, it is necessary to find a method that can achieve the deoxygenation of terminal alcohols under mild conditions and extend the carbon chain to ultimately obtain straight-chain compounds.

[0004] The present invention adopts a method of first halogenating the hydroxyl groups of the biomass polyol and then dehalogenating and coupling to achieve the deoxygenation and chain growth reaction of the terminal alcohol, which does not require a high temperature of more than 200° C. and does not require a strong redox agent, thereby ensuring the safety of the process. Summary of the invention

[0005] The significance of the present invention lies in providing a method for obtaining compounds with longer carbon chains from terminal alcohols under mild conditions by combining acid catalysis with photocatalysis.

[0006] In the first step, in the presence of an acid catalyst, a terminal alcohol (R-OH) reacts with an alkali metal salt of a halogen element (MX) to obtain a terminal halogenated compound (RX);

[0007] In the second step, in the presence of a photocatalyst and a base, the two terminal halogenated compounds are dehalogenated and then connected by carbon-carbon bonds to obtain a compound whose carbon number on the carbon chain is twice the number of carbons on the carbon chain of the original terminal alcohol in the first step.

[0008] (1) adding a terminal alcohol, an acid catalyst, an alkali metal salt of a halogen element, and a solvent into a reaction kettle, wherein the volume fraction of the terminal alcohol in the reaction system is 1% to 100%, the molar amount of the alkali metal salt of the halogen element is 0.01 to 5 times the molar amount of the terminal alcohol, and the concentration of the catalyst is 20 to 400 g / L; closing the reaction kettle, replacing the gas in the reaction kettle with argon and / or nitrogen, stirring and heating the reaction kettle, the temperature being 50 to 150° C.; separating and obtaining a terminal halogenated compound after the reaction is completed;

[0009] (2) adding the terminal halogenated compound obtained in step (1), a photocatalyst, a base, and a solvent into a reaction kettle, wherein the volume fraction of the terminal halogenated compound in the reaction system is 1% to 10%, and the molar amount of the base is 1 to 10 times that of the terminal halogenated compound; sealing the reaction kettle, replacing the gas in the reaction kettle with argon and / or nitrogen, stirring and placing the reaction kettle under light with a wavelength of 200 to 800 nm to react; after the reaction is completed, separating and obtaining a compound having a carbon number twice the carbon number of the terminal alcohol carbon chain in the first step.

[0010] The terminal alcohol ROH includes one or more of the following structures:

[0011]

[0012] The terminal halogenated compound (RX) obtained in step (1) has a structure corresponding to one or more of the following structural formulas:

[0013]

[0014] The compound obtained in step (2) has a carbon number twice as large as the carbon number of the terminal alcohol in the first step, and the corresponding structure is one or more of the following structural formulas:

[0015]

[0016] Acid catalysts include HY, HZSM-5, AB-15, SO4 2- / ZrO2、SO4 2- / one or more of TiO2;

[0017] The metal salt of the halogen element (MX) includes one or more of sodium bromide, sodium iodide, potassium bromide, potassium iodide, lithium bromide, and lithium iodide.

[0018] The photocatalyst in step (2) comprises a combination of a semiconductor, a metal salt and an organic ligand,

[0019] The semiconductor is one or more of titanium dioxide, cadmium sulfide, and carbon nitride, and the concentration of the semiconductor added to the reaction system is 1 to 50 g / L;

[0020] The metal salt is one or more of nickel chloride, ruthenium chloride and iridium chloride, and the concentration of the metal salt added to the reaction system is 1 to 10 mmol / L;

[0021] The organic ligand is one or more of terpyridine, bipyridine and triphenylphosphine, and the molar amount of the added organic ligand is 10% to 200% of the molar amount of the metal salt.

[0022] The base in step (2) includes one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, and potassium hydroxide, and the molar amount of the added base is 1 to 10 times the molar amount of the terminal halogenated compound;

[0023] The solvent in step (1) and step (2) is one or more of methanol, acetonitrile, dichloromethane and the terminal alcohol.

[0024] Step (1) wherein the volume fraction of the terminal alcohol is preferably 5% to 50%, the molar amount of MX is preferably 1.2 to 2.5 times that of the terminal alcohol, the concentration of the catalyst is preferably 50 to 200 g / L, and the reaction temperature is 80 to 120° C.;

[0025] In step (2), the volume fraction of the terminal halogenated compound is preferably 2% to 5%, the molar amount of the base is preferably 2 to 5 times that of the terminal halogenated compound, and the wavelength of the light is preferably 300 to 500 nm;

[0026] The concentration of the added semiconductor is preferably 2-10 g / L, the concentration of the added metal salt is preferably 2-5 mmol / L, and the molar amount of the added organic ligand is preferably 20%-100% of the metal salt.

[0027] The reaction time of step (1) is 1 to 20 hours, preferably 3 to 12 hours;

[0028] The reaction time of step (2) is 0.1 to 12 hours, preferably 1 to 6 hours.

[0029] After the reaction in step (1) is completed, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by hydrogen nuclear magnetic resonance spectroscopy to obtain a terminal halogenated compound;

[0030] After the reaction in step (2) is completed, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain a compound having a carbon number twice the carbon number of the terminal alcohol carbon chain in the first step.

[0031] Compared with the prior art, the reaction conditions of the present invention are mild, and high temperatures above 150° C. or 200° C. or above are not required, nor strong redox agents are required to achieve the carbon chain extension reaction of hydroxyl-containing compounds, thereby ensuring the safety of the process. DETAILED DESCRIPTION

[0032] In order to further explain the present invention in detail, several specific implementation cases are given below, but the present invention is not limited to these embodiments.

[0033] Embodiment 1:

[0034] Step (1): Add 20 mL of methanol solvent, 1% volume fraction of terminal alcohol 1, sodium bromide with a molar amount of 1 times that of the terminal alcohol, and HY with a concentration of 20 g / L into a reactor. The reactor is sealed, the gas in the reactor is replaced with argon, and the reaction is stirred and heated to 50°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 11 (Formula 11, the same below), and the yield calculated by gas chromatography is 30%;

[0035] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 1% volume fraction of terminal halogenated compound 11, 1 g / L titanium dioxide, 1 mmol / L nickel chloride, 10% molar amount of terpyridine of nickel chloride, and 1 times molar amount of sodium carbonate of terminal halogenated compound to the reactor. Seal the reactor, replace the gas in the reactor with nitrogen, stir and place under 200 nm light for reaction. After 8 hours of reaction, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 21 (Formula 21, the same below), and the yield calculated by gas chromatography is 80%.

[0036] Embodiment 2:

[0037] Step (1): Add 20 mL of acetonitrile solvent, 5% volume fraction of terminal alcohol 2, potassium bromide with a molar amount of 1.2 times that of the terminal alcohol, and HZSM-5 with a concentration of 50 g / L into a reactor. The reactor is sealed, the gas in the reactor is replaced with nitrogen, and the reaction is stirred and heated to 80°C. After reacting for 20 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain the terminal halogenated compound 12, and the yield calculated by gas chromatography is 70%;

[0038] Step (2): Add 0.8 mL of dichloromethane and 0.2 mL of methanol, 2% volume fraction of terminal halogenated compound 12, 2 g / L cadmium sulfide, 2 mmol / L ruthenium chloride, 20% molar bipyridine of ruthenium chloride, and 2 times molar potassium carbonate of terminal halogenated compound to a reactor. Seal the reactor, replace the gas in the reactor with argon, stir and place under 300 nm light for reaction. After reacting for 5 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 22, and the yield calculated by gas chromatography is 50%.

[0039] Embodiment 3:

[0040] Step (1): Add 20 mL of solvent dichloromethane, 50% volume fraction of terminal alcohol 3, sodium iodide with a molar amount of 0.05 times that of terminal alcohol, and AB-15 with a concentration of 200 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with nitrogen, and the reaction is stirred and heated to 120°C. After reacting for 1 hour, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 13, and the yield calculated by gas chromatography is 20%;

[0041] Step (2): Add 0.8 mL of terminal alcohol 3 and 0.2 mL of methanol, 5% volume fraction of terminal halogenated compound 13, carbon nitride at a concentration of 10 g / L, iridium chloride at a concentration of 5 mmol / L, triphenylphosphine at a molar weight of 100% of iridium chloride, and sodium bicarbonate at a molar weight of 5 times that of the terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 400 nm light for reaction. After reacting for 11 hours, filter to remove the solid, evaporate the solvent, filter to remove the precipitated salt again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 23, and the yield calculated by gas chromatography is 40%.

[0042] Embodiment 4:

[0043] Step (1): Add 20 mL of terminal alcohol 4, i.e., 100% by volume of terminal alcohol 4, 0.01 times the molar amount of potassium iodide of the terminal alcohol, and 400 g / L of SO4 into the reaction kettle. 2- / ZrO2. The reaction kettle was sealed, the gas in the reaction kettle was replaced with nitrogen, and the reaction was stirred and heated to 150°C. After reacting for 7 hours, the solid was filtered out, the solvent was evaporated, and the precipitated salt was filtered out again. Finally, the product was subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 14. The yield calculated by gas chromatography was 12%;

[0044] Step (2): Add 0.8 mL of terminal alcohol 4 and 0.2 mL of acetonitrile, 10% by volume of terminal halogenated compound 14, 20 g / L of titanium dioxide and 30 g / L of cadmium sulfide, 5 mmol / L of iridium chloride and 5 mmol / L of nickel chloride, 200% of the sum of iridium chloride and nickel chloride in molar weight of terpyridine, and 10 times of potassium bicarbonate in molar weight of terminal halogenated compound in a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and react under 500 nm light. After reacting for 0.1 hour, filter to remove solid, evaporate the solvent, filter to remove precipitated salt again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 24, and the yield calculated by gas chromatography is 36%.

[0045] Embodiment 5:

[0046] Step (1): Add 10 mL of dichloromethane and 10 mL of acetonitrile, 10% by volume of terminal alcohol 5, twice the molar amount of lithium bromide as the terminal alcohol, and 100 g / L of SO4 into a reaction kettle. 2- / TiO2. The reaction kettle was sealed, the gas in the reaction kettle was replaced with nitrogen, and the reaction was stirred and heated to 90°C. After reacting for 19 hours, the solid was filtered out, the solvent was evaporated, and the precipitated salt was filtered out again. Finally, the product was subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 15. The yield calculated by gas chromatography was 48%;

[0047] Step (2): Add 0.8 mL of acetonitrile and 0.2 mL of methanol, 3% volume fraction of terminal halogenated compound 15, 5 g / L titanium dioxide, 4 mmol / L nickel chloride, 80% molar weight of terpyridine and 10% molar weight of bipyridine of nickel chloride, and 4 times molar weight of sodium hydroxide of terminal halogenated compound to the reactor. Seal the reactor, replace the gas in the reactor with argon, stir and place under 600 nm light for reaction. After reacting for 0.5 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 25, and the yield calculated by gas chromatography is 62%.

[0048] Embodiment 6:

[0049] Step (1): Add 20 mL of acetonitrile solvent, 10% volume fraction of terminal alcohol 6, lithium iodide with a molar weight 2.2 times that of terminal alcohol, and SO4 with a concentration of 120 g / L into a reaction kettle. 2- / TiO2. The reaction kettle was sealed, the gas in the reaction kettle was replaced with nitrogen, and the reaction was stirred and heated to 100°C. After reacting for 3 hours, the solid was filtered out, the solvent was evaporated, and the precipitated salt was filtered out again. Finally, the product was subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 16. The yield calculated by gas chromatography was 44%;

[0050] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 4% volume fraction of terminal halogenated compound 16, 8 g / L cadmium sulfide, 3 mmol / L ruthenium chloride, 70% molar amount of terpyridine of ruthenium chloride, and 3 times molar amount of potassium hydroxide of terminal halogenated compound to a reactor. Seal the reactor, replace the gas in the reactor with argon, stir and place under 700 nm light for reaction. After reacting for 0.5 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 26, and the yield calculated by gas chromatography is 53%.

[0051] Embodiment 7:

[0052] Step (1): Add 20 mL of acetonitrile solvent, 10% volume fraction of terminal alcohol 7, lithium iodide with a molar weight 3.2 times that of terminal alcohol, and SO4 with a concentration of 220 g / L into a reaction kettle. 2- / TiO2. The reaction kettle was sealed, the gas in the reaction kettle was replaced with nitrogen, and the reaction was stirred and heated to 70°C. After reacting for 14 hours, the solid was filtered out, the solvent was evaporated, and the precipitated salt was filtered out again. Finally, the product was subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 17. The yield calculated by gas chromatography was 38%;

[0053] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 9% volume fraction of terminal halogenated compound 17, 8 g / L carbon nitride, 1.8 mmol / L nickel chloride, 70% molar weight of terpyridine of nickel chloride, 1 times molar weight of potassium hydroxide and 1 times molar weight of sodium hydroxide of terminal halogenated compound to a reactor. Seal the reactor, replace the gas in the reactor with argon, stir and place under 800 nm light for reaction. After reacting for 1 hour, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 27, and the yield calculated by gas chromatography is 37%.

[0054] Embodiment 8:

[0055] Step (1): Add 20 mL of solvent dichloromethane, 4% volume fraction of terminal alcohol 8, potassium iodide with a molar weight 5 times that of the terminal alcohol, and AB-15 with a concentration of 150 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with nitrogen, and the reaction is stirred and heated to 110°C. After reacting for 4 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 18, and the yield calculated by gas chromatography is 26%;

[0056] Step (2): Add 0.3 mL of dichloromethane and 0.7 mL of methanol, 6% volume fraction of terminal halogenated compound 18, 5 g / L titanium dioxide, 6.6 mmol / L nickel chloride, 40% molar weight of terpyridine of nickel chloride, and 1 times molar weight of potassium hydroxide of terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 350 nm light for reaction. After reacting for 2 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 28, and the yield calculated by gas chromatography is 61%.

[0057] Embodiment 9:

[0058] Step (1): Add 20 mL of acetonitrile solvent, 10% volume fraction of terminal alcohol 9, lithium iodide with a molar amount of 1.2 times that of terminal alcohol, and HZSM-5 with a concentration of 200 g / L into a reactor. The reactor is sealed, the gas in the reactor is replaced with nitrogen, and the reaction is stirred and heated to 60°C. After reacting for 12 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 19, and the yield calculated by gas chromatography is 55%;

[0059] Step (2): Add 0.3 mL of acetonitrile and 0.7 mL of methanol, 2% volume fraction of terminal halogenated compound 19, 33 g / L titanium dioxide, 7 mmol / L nickel chloride, 130% molar weight of terpyridine of nickel chloride, and 3 times molar weight of potassium carbonate of terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 300-700 nm light for reaction. After 12 hours of reaction, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 29, and the yield calculated by gas chromatography is 41%.

[0060] Embodiment 10:

[0061] Step (1): Add 20 mL of acetonitrile solvent, 10% volume fraction of terminal alcohol 10, lithium bromide with a molar amount 2.5 times that of terminal alcohol, and HZSM-5 with a concentration of 200 g / L into a reactor. The reactor is sealed, the gas in the reactor is replaced with nitrogen, and the reaction is stirred and heated to 105° C. After reacting for 1 hour, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 20, and the yield calculated by gas chromatography is 25%;

[0062] Step (2): Add 0.3 mL of acetonitrile and 0.7 mL of methanol, 2% volume fraction of terminal halogenated compound 20, 5.5 g / L titanium dioxide, 7 mmol / L ruthenium chloride, 90% molar triphenylphosphine of ruthenium chloride, and 2.5 times molar sodium carbonate of terminal halogenated compound to a reactor. Seal the reactor, replace the gas in the reactor with argon, stir and place under 450 nm illumination to react. After reacting for 6 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 30, and the yield calculated by gas chromatography is 37%.

[0063] Embodiment 11:

[0064] Step (1): Add 20 mL of acetonitrile solvent, 5% volume fraction of terminal alcohol 6, sodium iodide with a molar amount twice that of the terminal alcohol, and AB-15 with a concentration of 200 g / L into a reactor. The reactor is sealed, the gas in the reactor is replaced with argon, and the reaction is stirred and heated to 90°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 16, and the yield calculated by gas chromatography is 67%;

[0065] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 2% volume fraction of terminal halogenated compound 16, 5 g / L titanium dioxide, 2 mmol / L nickel chloride, 20% molar amount of terpyridine of nickel chloride, and 2 times molar amount of sodium carbonate of terminal halogenated compound to the reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 200-400 nm light for reaction. After 4 hours of reaction, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 26, and the yield calculated by gas chromatography is 70%.

[0066] Embodiment 12:

[0067] Step (1): Add 20 mL of acetonitrile solvent, 2% volume fraction of terminal alcohol 1, sodium iodide with a molar weight twice that of the terminal alcohol, and AB-15 with a concentration of 200 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with argon, and the reaction is stirred and heated to 90°C. After reacting for 12 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 11, and the yield calculated by gas chromatography is 72%;

[0068] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 2% volume fraction of terminal halogenated compound 11, 5 g / L titanium dioxide, 2 mmol / L nickel chloride, 20% molar amount of terpyridine of nickel chloride, and 2 times molar amount of sodium carbonate of terminal halogenated compound to the reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 400-800 nm light for reaction. After reacting for 10 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 21, and the yield calculated by gas chromatography is 66%.

[0069] Embodiment 13:

[0070] Step (1): Add 20 mL of solvent terminal alcohol 6, i.e., 100% volume fraction of terminal alcohol 6, sodium iodide with a molar amount of 0.01 times that of terminal alcohol, and AB-15 with a concentration of 200 g / L, to a reactor. The reactor is sealed, the gas in the reactor is replaced with argon, and the reaction is stirred and heated to 90°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 16, and the yield calculated by gas chromatography is 6%;

[0071] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of terminal alcohol 6, 2% by volume of terminal halogenated compound 16, 5 g / L of titanium dioxide, 2 mmol / L of nickel chloride, 100% by molar amount of terpyridine of nickel chloride, and 2 times by molar amount of sodium carbonate of terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 550 nm light for reaction. After 6 hours of reaction, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 26, with a yield of 48% calculated by gas chromatography.

[0072] Embodiment 14:

[0073] Step (1): Add 20 mL of acetonitrile solvent, 10% volume fraction of terminal alcohol 1, sodium iodide with a molar amount of 0.1 times that of terminal alcohol, and AB-15 with a concentration of 200 g / L into a reaction kettle. The reaction kettle is sealed, and the gas in the reaction kettle is replaced with argon gas. The reaction is stirred and heated to 90°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 11. The yield calculated by gas chromatography is 17%;

[0074] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 2% volume fraction of terminal halogenated compound 11, 5 g / L titanium dioxide, 2 mmol / L nickel chloride, 100% molar weight of terpyridine of nickel chloride, and 1 times molar weight of sodium hydroxide of terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 365 nm light for reaction. After reacting for 5 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 21, and the yield calculated by gas chromatography is 39%.

[0075] Embodiment 15:

[0076] Step (1): Add 20 mL of acetonitrile solvent, 5% volume fraction of terminal alcohol 6, sodium iodide with a molar amount of 0.8 times that of the terminal alcohol, and AB-15 with a concentration of 300 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with argon, and the reaction is stirred and heated to 90°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 16, and the yield calculated by gas chromatography is 29%;

[0077] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 2% by volume of terminal halogenated compound 16, 5 g / L of cadmium sulfide, 2 mmol / L of nickel chloride, 100% by molar amount of terpyridine of nickel chloride, and 1 times by molar amount of sodium hydroxide of terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under 455 nm light for reaction. After reacting for 5 hours, filter to remove solids, evaporate the solvent, filter to remove precipitated salts again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 26, and the yield calculated by gas chromatography is 22%.

[0078] Comparative Example 1:

[0079] Step (1): Add 20 mL of acetonitrile solvent, 5% volume fraction of terminal alcohol 1, sodium iodide with a molar amount of 0.8 times that of the terminal alcohol, and AB-15 with a concentration of 1 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with argon, and the reaction is stirred and heated to 90° C. After reacting for 10 hours, the product is separated by normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum. The yield of terminal halogenated compound 11 calculated by gas chromatography is 1%;

[0080] Step (2): Add 0.9 mL of acetonitrile and 0.1 mL of methanol, 2% by volume of terminal halogenated compound 11, 5 g / L of cadmium sulfide, 2 mmol / L of nickel chloride, and 1 times the molar amount of sodium hydroxide as the terminal halogenated compound to a reaction kettle. Seal the reaction kettle, replace the gas in the reaction kettle with argon, stir and place under light for reaction. After reacting for 5 hours, separate the product by normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum. The yield of compound 21 calculated by gas chromatography is 2%.

[0081] Comparative Example 2:

[0082] Step (1): Add 20 mL of solvent cyclohexane, 5% volume fraction of terminal alcohol 1, sodium iodide with a molar weight of 0.8 times that of terminal alcohol, and AB-15 with a concentration of 300 g / L into a reaction kettle. The reaction kettle is sealed, the gas in the reaction kettle is replaced with argon, and the reaction is stirred and heated to 90°C. After reacting for 10 hours, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain terminal halogenated compound 11, and the yield calculated by gas chromatography is 0.3%;

[0083] Step (2): Add 1 mL of acetonitrile, 2% by volume of terminal halogenated compound 11, 5 g / L of cadmium sulfide, 2 mmol / L of nickel chloride, and terpyridine in a molar amount of 100% of nickel chloride to a reaction kettle. Seal the kettle, replace the gas in the reaction kettle with argon, stir and place under light for reaction. After reacting for 5 hours, filter to remove the solid, evaporate the solvent, filter to remove the precipitated salt again, and finally perform normal pressure silica gel column chromatography and analyze the product by hydrogen nuclear magnetic resonance spectrum to obtain compound 21, and the yield calculated by gas chromatography is 3%.

Claims

1. A two-step method for extending the carbon chain of a terminal alcohol, characterized in that: In the first step, in the presence of an acid catalyst, a terminal alcohol (R-OH) reacts with an alkali metal salt of a halogen element (MX) to obtain a terminal halogenated compound (RX); In the second step, in the presence of a photocatalyst and a base, the two terminal halogenated compounds are dehalogenated and then connected by carbon-carbon bonds to obtain a compound whose carbon number on the carbon chain is twice the number of carbons on the carbon chain of the original terminal alcohol in the first step.

2. The method according to claim 1, characterized in that The following steps are involved: (1) adding a terminal alcohol, an acid catalyst, an alkali metal salt of a halogen element, and a solvent into a reaction kettle, wherein the volume fraction of the terminal alcohol in the reaction system is 1% to 100%, the molar amount of the alkali metal salt of the halogen element is 0.01 to 5 times the molar amount of the terminal alcohol, and the concentration of the acid catalyst is 20 to 400 g / L; closing the reaction kettle, replacing the gas in the reaction kettle with argon and / or nitrogen, stirring and heating the reaction kettle to a temperature of 50 to 150° C.; separating and obtaining a terminal halogenated compound after the reaction is completed; (2) adding the terminal halogenated compound obtained in step (1), a photocatalyst, a base, and a solvent into a reaction kettle, wherein the volume fraction of the terminal halogenated compound in the reaction system is 1% to 10%, and the molar amount of the base is 1 to 10 times that of the terminal halogenated compound; sealing the reaction kettle, replacing the gas in the reaction kettle with argon and / or nitrogen, stirring and placing the reaction kettle under light with a wavelength of 200 to 800 nm to react; after the reaction is completed, separating and obtaining a compound having a carbon number twice the carbon number of the terminal alcohol carbon chain in the first step.

3. The method according to claim 1 or 2, characterized in that: The terminal alcohol ROH comprises one or more of the following structures: The terminal halogenated compound (RX) obtained in step (1) has a structure corresponding to one or more of the following structural formulas: The compound obtained in step (2) has a carbon number twice as large as the carbon number of the terminal alcohol in the first step, and the corresponding structure is one or more of the following structural formulas:

4. The method according to claim 1 or 2, characterized in that: The acid catalyst includes HY, HZSM-5, AB-15, SO4 2- / ZrO2、SO4 2- / one or more of TiO2; The metal salt of the halogen element (MX) includes one or more of sodium bromide, sodium iodide, potassium bromide, potassium iodide, lithium bromide and lithium iodide.

5. The method according to claim 1 or 2, characterized in that: The photocatalyst in step (2) comprises a combination of a semiconductor, a metal salt and an organic ligand, The semiconductor is one or more of titanium dioxide, cadmium sulfide, and carbon nitride, and the concentration of the semiconductor added to the reaction system is 1 to 50 g / L; The metal salt is one or more of nickel chloride, ruthenium chloride and iridium chloride, and the concentration of the metal salt added to the reaction system is 1 to 10 mmol / L; The organic ligand is one or more of terpyridine, bipyridine and triphenylphosphine, and the molar amount of the added organic ligand is 10% to 200% of the molar amount of the metal salt.

6. The method according to claim 1 or 2, characterized in that: The base in step (2) includes one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, and potassium hydroxide, and the molar amount of the added base is 1 to 10 times the molar amount of the terminal halogenated compound; The solvents described in step (1) and step (2) are one or more of methanol, acetonitrile, dichloromethane and the terminal alcohol.

7. The method according to claim 2, characterized in that: Step (1) wherein the volume fraction of the terminal alcohol is preferably 5% to 50%, the molar amount of MX is preferably 1.2 to 2.5 times that of the terminal alcohol, the concentration of the catalyst is preferably 50 to 200 g / L, and the reaction temperature is 80 to 120° C.; In step (2), the volume fraction of the terminal halogenated compound is preferably 2% to 5%, the molar amount of the base is preferably 2 to 5 times that of the terminal halogenated compound, and the wavelength of the light is preferably 300 to 500 nm.

8. The method according to claim 5, characterized in that: The concentration of the added semiconductor is preferably 2-10 g / L, the concentration of the added metal salt is preferably 2-5 mmol / L, and the molar amount of the added organic ligand is preferably 20%-100% of the metal salt.

9. The method according to claim 2, characterized in that: The reaction time of step (1) is 1 to 20 hours, preferably 3 to 12 hours; The reaction time of step (2) is 0.1 to 12 hours, preferably 1 to 6 hours.

10. The method according to claim 2 or 9, characterized in that: After the reaction in step (1) is completed, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by hydrogen nuclear magnetic resonance spectroscopy to obtain a terminal halogenated compound; After the reaction in step (2) is completed, the solid is filtered out, the solvent is evaporated, and the precipitated salt is filtered out again. Finally, the product is subjected to normal pressure silica gel column chromatography and analyzed by nuclear magnetic resonance hydrogen spectrum to obtain a compound having a carbon number twice the carbon number of the terminal alcohol carbon chain in the first step.

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