A solution to achieve good reusability of MNPs Fe3O4-supported (S)-diphenylprolinoltrimethylsilyl ether catalysts in asymmetric Michael reactions

RSC Advances ◽  
2016 ◽  
Vol 6 (30) ◽  
pp. 25246-25254 ◽  
Author(s):  
Tao Wu ◽  
Dandan Feng ◽  
Bing Xie ◽  
Xuebing Ma

A PVP-modified MNPs Fe3O4-supported Jøgensen–Hayashi catalyst to achieved good reusability with high yields and unchangeable excellent stereoselectivities in the asymmetric Michael addition of propanal to nitroalkenes.

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2577-2586 ◽  
Author(s):  
Jia-Ni Yuan ◽  
Hui-Xia Liu ◽  
Qin-Qin Tian ◽  
Nan Ji ◽  
Kuo Shen ◽  
...  

We report a highly efficient asymmetric Michael addition of dithiomalonates to trans-β-nitroolefins catalyzed by versatile cinchona-based bifunctional thioureas, which provides the corresponding adducts in high yields (up to 92%) and with excellent enantioselectivities (up to 99% ee) under mild conditions. Replacement of the catalyst with its pseudo-enantiomer gives the Michael adducts with opposite configuration in similar yields and enantioselectivities.


Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Ning Lin ◽  
Qiu-Xiang Wei ◽  
Li-Hua Jiang ◽  
Yan-Qiu Deng ◽  
Zhen-Wei Zhang ◽  
...  

A rosin-derived bifunctional squaramide catalyzed asymmetric Michael addition of malononitrile with chalcones was discovered. This protocol provides a methodology for the facile synthesis of chiral γ-cyano carbonyl compounds in high yields and enantioselectivities (up to 99% yield and 90% ee) with a lower catalyst loading (0.3 mol%). The predominant R-configured adducts were obtained by this organocatalystic reaction, according to the experimental findings.


Synthesis ◽  
2022 ◽  
Author(s):  
Zhi-Wei Ma ◽  
Chuan-Chuan Wang ◽  
Quan-Jian Lv ◽  
Xiao-Pei Chen ◽  
Ai-Qin Li ◽  
...  

AbstractA new tertiary amine-squaramide organocatalyst has been developed and applied to the asymmetric Michael addition of cyclic diketones to β,γ-unsaturated α-keto esters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of synthetically and pharmaceutically useful chiral bicyclic compounds were obtained in high yields (up to 97%) with excellent enantioselectivities (up to 99 % ee). Furthermore, this catalytic system can be used efficiently in large-scale reactions with the yields and enantioselectivities being maintained.


2020 ◽  
Vol 18 (8) ◽  
pp. 1647-1656 ◽  
Author(s):  
Jiang-Bo Wen ◽  
Da-Ming Du

An efficient squaramide-catalysed asymmetric Michael addition/cyclization cascade reaction of 3-chlorooxindoles with 2,3-dioxopyrrolidines produced the corresponding chiral spiro-compounds in high yields with excellent stereoselectivities.


2018 ◽  
Vol 14 ◽  
pp. 1901-1907 ◽  
Author(s):  
Zheng-Yi Li ◽  
Hong-Xiao Tong ◽  
Yuan Chen ◽  
Hong-Kui Su ◽  
Tangxin Xiao ◽  
...  

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.


2020 ◽  
Vol 24 (7) ◽  
pp. 746-773
Author(s):  
Péter Bakó ◽  
Tamás Nemcsok ◽  
Zsolt Rapi ◽  
György Keglevich

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.


2010 ◽  
Vol 16 (23) ◽  
pp. 7030-7038 ◽  
Author(s):  
Ying-Fang Ting ◽  
Chihliang Chang ◽  
Raju Jannapu Reddy ◽  
Dhananjay R. Magar ◽  
Kwunmin Chen

ChemInform ◽  
2015 ◽  
Vol 46 (12) ◽  
pp. no-no
Author(s):  
Ahmed Kamal ◽  
Manda Sathish ◽  
Vunnam Srinivasulu ◽  
Jadala Chetna ◽  
Kunta Chandra Shekar ◽  
...  

2017 ◽  
Vol 13 ◽  
pp. 612-619 ◽  
Author(s):  
Alejandro Castán ◽  
Ramón Badorrey ◽  
José A Gálvez ◽  
María D Díaz-de-Villegas

New pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derived from (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved.


2016 ◽  
Vol 81 (21) ◽  
pp. 10506-10516 ◽  
Author(s):  
Hong-Xiu Huang ◽  
Hui-Jing Wang ◽  
Ling Tan ◽  
Shu-Qing Wang ◽  
Pei Tang ◽  
...  

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