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CN-121974821-A - Photocatalytic stereoselective E-type olefination of alkynyl amide and preparation method thereof

CN121974821ACN 121974821 ACN121974821 ACN 121974821ACN-121974821-A

Abstract

The invention discloses a photocatalytic stereoselective E-type olefination of alkynyl amide and a preparation method thereof. The method is carried out in an aqueous phase micelle reaction system and is completed under the drive of visible light. According to the method, alkynyl amide compounds are used as raw materials, sodium ascorbate is used as a green reducing agent, ru (bpy) 3 (PF 6 ) 2 or [ Ir (dtbbpy) (ppy) 2 ]PF 6 ] is used as a photocatalyst in an aqueous phase micelle environment formed by Sodium Dodecyl Sulfate (SDS) serving as a surfactant, and catalytic circulation is initiated by irradiation of visible light at 20-40 ℃ under the protection of inert gas, so that E-type olefin products are converted in a high selectivity manner. The method has mild conditions, simple steps, high stereoselectivity, environmental friendliness and safe operation, avoids the problem that flammable and explosive reagents or harsh reaction conditions are needed in the traditional method, and provides a green and efficient preparation way for preparing the E-type enamide compounds.

Inventors

  • WANG JING
  • WANG HAN
  • WANG ZIXUAN

Assignees

  • 陕西科技大学

Dates

Publication Date
20260505
Application Date
20260312

Claims (10)

  1. 1. A photocatalytic stereoselective type E olefin of an alkynylamide, wherein the type E olefin has the formula: Wherein R 1 is selected from phenyl or heterocycle, R 2 is selected from hydrogen, alkyl or heterocycle, and R 3 is selected from hydrogen, alkyl, methoxy, phenyl or heterocycle.
  2. 2. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 1, comprising the steps of: ru (bpy) 3 (PF 6 ) 2 or [ Ir (dtbbpy) (ppy) 2 ]PF 6 , sodium ascorbate, surfactant and alkaline agent are dissolved in water to prepare micelle aqueous solution; adding alkynyl amide compounds into the micelle aqueous solution, and reacting under the irradiation of inert gas and a visible light source to obtain the E-type olefin.
  3. 3. The method for preparing an alkynylamide-based photocatalytic stereoselective olefin according to claim 2, wherein the alkynylamide compound is selected from the group consisting of 3-phenylpropionamide, 3- (4-methyl) phenylpropionamide, 3- (4-tert-butyl) phenylpropionamide, 3- (4-thiomethyl) phenylpropionamide, 3- (4-dimethylamino) phenylpropionamide, 3- ([ 1,1' -biphenyl ] -4-phenyl) propynamide, 3- (4-fluorophenyl) -2-acrylamide, 3- (4-chlorophenyl) -2-acrylamide, 3- (4-bromophenyl) phenylpropionamide, 3- (4- (trifluoromethyl) phenyl) propynamide, 3- (2-chlorophenyl) propynamide, 3-naphthyl propynamide, 3- (3-pyridyl) propynamide, 3- (3-thienyl) propynamide, 4-phenyl-3-butyn-2-one, p-chlorobenzoic acid, p-bromophenylpropynamic acid, p-methylbenzoic acid, p-2-chlorobenzoic acid, p-chlorobenzoic acid, 2-propargyl-2-butan-one, p-chlorobenzoic acid, 2-butan-2-propargyl acid, p-chlorobenzoic acid, 2-chlorobenzoic acid, and the like, at least one of 1-naphthylbenzalacetone, 3- (4-chlorophenyl) methyl propiolate and 3- (4-bromophenyl) methyl propiolate.
  4. 4. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 2, wherein the surfactant is sodium dodecyl sulfate.
  5. 5. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 2, wherein the inert gas is argon and the visible light source is a blue LED lamp.
  6. 6. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 2, wherein the reaction temperature is 20 ℃ to 40 ℃ and the reaction time is 12 h to 48 h.
  7. 7. The method for preparing the photocatalytic stereoselective E olefin of alkynyl amide according to claim 2, wherein the molar ratio of sodium ascorbate to surfactant is 1.0:2.0-1.0:3.0, and the molar ratio of Ru (bpy) 3 (PF 6 ) 2 or [ Ir (dtbbpy) (ppy) 2 ]PF 6 to sodium ascorbate is 0.06:0.22.
  8. 8. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 2, wherein the concentration of the alkynyl amide compound in the aqueous solution of micelle is 0.1 to 0.2 mol/l.
  9. 9. The method for preparing the photocatalytic stereoselective E-olefin of alkynyl amide according to claim 2, wherein the alkaline reagent is aqueous NaOH.
  10. 10. The method for preparing the photocatalytic stereoselective E-olefin of the alkynylamide according to claim 2, wherein the preparation reaction formula of the photocatalytic stereoselective E-olefin of the alkynylamide is: 。

Description

Photocatalytic stereoselective E-type olefination of alkynyl amide and preparation method thereof Technical Field The invention belongs to the technical field of organic preparation and green chemistry, and particularly relates to a photocatalytic conversion method of alkynyl amide compounds, in particular to a method for preparing amide E-type olefins with high stereoselectivity in an aqueous phase micelle system under visible light driving. Background Amide type E olefins are of great interest in bioactive molecules and functional materials because of their unique configuration and properties. Alkynylamides are ideal precursors for the preparation of such compounds, and direct reduction of olefination is an efficient preparation route. The existing method for preparing E-type olefin is more [a) ]Yu R., Xing Y., Fang X., Organic Letters, 2021, 23(3): 930-935. b) Li B., Chen J., Zhang Z., Angewandte Chemie, 2019, 131(22): 7407-7412.],, wherein the reaction needs hydrogenation, the operation is dangerous, the reaction environment temperature is high, the conditions are harsh, the reaction steps are too many, the E/Z isomer ratio generated by the transition metal catalysis (such as Pd catalysis Heck reaction) is only 7:3-8:2, and the subsequent separation cost accounts for more than 40% of the total process cost. Therefore, it is of great importance to develop a green preparation method which is mild in conditions, safe in operation, and capable of achieving excellent stereoselectivity. The visible light catalysis uses clean light energy as driving force, the reaction condition is mild, a new approach is provided for developing a green preparation technology, and the potential .[c) Chen F., Zhang Y., Yu L., Angewandte Chemie, 2017, 129(8): 2054-2057 d) Xu H., Yang P., Chuanprasit P., Angewandte Chemie International Edition, 2015, 54(17): 5112-5116 e) Park B Y., Lim T., Han M S., Chemical Communications, 2021, 57(56): 6891-6894.]. is shown in various organic transformations, and although the photocatalysis has shown the potential in various transformations, the application of the visible light catalysis to direct and high-selectivity E-type olefination of alkynyl amide, particularly the realization of high-efficiency transformation in an environment-friendly aqueous medium, still has obvious challenges. Therefore, the E-type olefination method which can be carried out in the water phase, is driven by visible light and has high stereoselectivity is developed, and has important scientific significance and application value. Disclosure of Invention Aiming at the problems in the prior art, the preparation method of the photocatalytic stereoselective E-type olefination of alkynyl amide is carried out in an aqueous phase micelle reaction system and is completed under the drive of visible light. According to the method, alkynyl amide compounds are used as raw materials, sodium ascorbate is used as a green reducing agent, catalytic circulation is initiated by irradiation of visible light in an aqueous phase micelle environment formed by a surfactant, alkynyl is subjected to a photocatalytic reduction process to generate an alkyne free radical anion intermediate in situ, and then the alkyne free radical anion intermediate is subjected to one-step protonation and is converted into an E-type olefin product with high selectivity. The invention is realized by the following technical scheme: a photocatalytic stereoselective E-olefin of an alkynylamide having the formula: Wherein R 1 is selected from phenyl or heterocycle, R 2 is selected from hydrogen, alkyl or heterocycle, and R 3 is selected from hydrogen, alkyl, methoxy, phenyl or heterocycle. The preparation method of the photocatalytic stereoselective E-olefin of alkynyl amide comprises the following steps: ru (bpy) 3(PF6)2 or [ Ir (dtbbpy) (ppy) 2]PF6, sodium ascorbate, surfactant and alkaline agent are dissolved in water to prepare micelle aqueous solution; adding alkynyl amide compounds into the micelle aqueous solution, and reacting under the irradiation of inert gas and a visible light source to obtain the E-type olefin. Preferably, the alkynylamide compound is selected from the group consisting of 3-phenylpropionamide, 3- (4-methyl) phenylpropionamide, 3- (4-tert-butyl) phenylpropionamide, 3- (4-thiomethyl) phenylpropionamide, 3- (4-dimethylamino) phenylpropionamide, 3- ([ 1,1' -biphenyl ] -4-phenyl) propioamide, 3- (4-fluorophenyl) -2-acrylamide, 3- (4-chlorophenyl) -2-acrylamide, 3- (4-bromophenyl) phenylpropionamide, 3- (4- (trifluoromethyl) phenyl) propioamide, 3- (2-chlorophenyl) propioamide, 3-naphtyl propioamide, 3- (3-pyridyl) propioamide, 3- (3-thienyl) propioamide, phenylpropionic acid, 4-phenyl-3-butyn-2-one, p-chlorophenylpropionic acid, p-methylphenyl propioamide, p-methoxyphenylpropinic acid, p-trifluoromethylphenylpropionic acid, o-chlorophenyl, 1-propiophenone, 3- (2-chlorophenyl) propiophenone, 2-4-propargyl, 4-chlorophenyl propionone, 4-phenylpr