Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for the regio- and stereoselective synthesis of (e)-2,4,4-trisubstituted conjugated dienes

A stereoselective, conjugated diene technology, applied in chemical instruments and methods, preparation of halogenated hydrocarbons, preparation of organic compounds, etc., can solve problems such as difficult, expensive reaction conditions, poor regio and stereoselectivity, and achieve The effect of mild reaction conditions, great practical application value, and easy operation

Active Publication Date: 2022-06-24
WENZHOU UNIV
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, these methods generally require the use of expensive noble metal catalysts, toxic reagents, harsh reaction conditions, and multi-step processes, while generating a large amount of solid-liquid waste, low atom economy, and unfriendly environment.
In addition, these methods generally synthesize less substituted linear conjugated dienes, which have poor regio and stereoselectivity, and there are still great difficulties in synthesizing multi-substituted conjugated dienes with high regio and stereoselectivity.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method for the regio- and stereoselective synthesis of (e)-2,4,4-trisubstituted conjugated dienes
  • A method for the regio- and stereoselective synthesis of (e)-2,4,4-trisubstituted conjugated dienes
  • A method for the regio- and stereoselective synthesis of (e)-2,4,4-trisubstituted conjugated dienes

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] A method for regio- and stereoselective synthesis of (E)-2,4,4-trisubstituted conjugated dienes, the method is as follows:

[0032]

[0033] Add CoCl to a dry reaction tube at 25°C 2 (0.025 mmol), PNP ligand (0.025 mmol), compound 1A (0.5 mmol) and toluene (1 mL), were injected into sodium triethylborohydride (0.075 mmol), and then stirred at room temperature for 12 h, followed by column chromatography Compound 1B was isolated as a colorless oily liquid in 99% yield.

[0034] The NMR characterization data of compound 1B are as follows:

[0035] 1 H NMR: (400.0 MHz, CDCl 3 )δ7.49-7.55(m,2H),7.43-7.48(m,2H),7.25-7.40(m,6H),6.56(s,1H),5.68(s,1H),5.24(s,1H) , 2.12(s, 3H).

Embodiment 2

[0037] A method for regio- and stereoselective synthesis of (E)-2,4,4-tri-substituted conjugated diene, which is basically the same as that of Example 1, except that vinylcyclopropane selects compound 2A, and the product is compound 2B , Compound 2B was a colorless oily liquid with a yield of 99%.

[0038]

[0039] The NMR characterization data of compound 2B are as follows:

[0040] 1 H NMR: (500.1 MHz, CDCl 3 )δ7.51(d,J=8.0Hz,1H),7.45(d,J=8.5Hz,2H),7.39(d,J=8.5Hz,1H),7.30-7.38(m,2H),7.24- 7.30(m, 1H), 6.82-6.93(m, 2H), 6.55(s, 1H), 5.66(s, 1H), 5.22(s, 1H), 3.81(s, 3H), 2.13(s, 3H) .

[0041] 13 C NMR: (125.8MHz, CDCl 3 ) δ159.3, 145.5, 144.6, 143.4, 141.1, 138.6, 138.1, 135.8, 133.4, 128.3, 127.7, 127.5, 127.2, 126.6, 125.9, 113.7, 55.3, 17.5.

Embodiment 3

[0043] A method for regio- and stereoselective synthesis of (E)-2,4,4-trisubstituted conjugated diene, which is basically the same as that of Example 1, except that vinylcyclopropane selects compound 3A, and the product is compound 3B , Compound 3B was a colorless oily liquid with a yield of 99%.

[0044]

[0045] The NMR characterization data of compound 3B are as follows:

[0046] 1 H NMR: (500.1 MHz, CDCl 3 )δ7.51(d,J=7.5Hz,1H),7.45(d,J=7.5Hz,1H),7.41(d,J=8.0Hz,1H),7.29-7.38(m,3H),7.24- 7.29(m, 1H), 7.10-7.16(t, 2H), 6.55(s, 1H), 5.66(s, 1H), 5.23(s, 1H), 2.35(s, 3H), 2.12(s, 3H) .

[0047] 13 C NMR: (125.8MHz, CDCl 3 ) δ145.4, 145.2, 143.5, 141.0, 140.6, 138.7, 138.0, 137.1, 129.1, 128.4, 127.7, 127.3, 126.7, 125.9, 115.3, 114.6, 21.2, 17.6.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for synthesizing (E)‑2,4,4‑trisubstituted conjugated dienes regioselectively and stereoselectively. 2 The combination with the PNP ligand is a catalyst, reacts in an organic solvent at room temperature to 100°C, and stereoselectively obtains (E)-2,4,4-trisubstituted conjugated dienes. The method of the present invention can stereoselectively synthesize (E)-2,4,4-trisubstituted conjugated diene, the catalyst and raw materials used are cheap and easy to obtain, the operation is simple, the reaction process does not need the participation of other external reagents, and the atom economy Well, it has a very high industrial application prospect.

Description

technical field [0001] The invention relates to a method for synthesizing (E)-2,4,4-trisubstituted conjugated dienes, in particular to a regio- and stereoselective synthesis of (E)-2,4,4-trisubstituted conjugated diolefins The method of alkenes. Background technique [0002] Conjugated dienes are the key structural units of many natural products and drug molecules. In addition, due to their strong reactivity, conjugated dienes have been continuously expanded in the fields of organic synthesis and polymer chemistry, and their application value is increasing day by day. Conjugated dienes can realize enantioselective hydrogen functionalization reactions, metal-catalyzed hydrosilylation reactions, hydroboration reactions, and Diels-Alder (D-A) cycloaddition reactions, etc. The synthetic applications of conjugated dienes are as follows: [0003] [0004] For a long time, people have devoted themselves to the development of efficient regio- and stereoselective synthesis of con...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C07C5/22C07C15/18C07C41/18C07C43/215C07C319/20C07C321/28C07C209/68C07C211/48C07C17/358C07C25/24C07C15/24C07D317/50
CPCC07C5/22C07C41/18C07C319/20C07C209/68C07C17/358C07D317/50C07C15/18C07C43/215C07C321/28C07C211/48C07C25/24C07C15/24
Inventor 陈建辉王伟夏远志罗燕书胡海洋郦余程
Owner WENZHOU UNIV