corresponding succinimides in good yields and enantioselectivities. DFT calculations support the stereochemical results and the role played by the solvents. Chiralprimary amines containing the (R,R)- and (S,S)-trans-cyclohexane-1,2-diamine scaffold and a pyrimidin-2-yl unit are synthesized and used as general organocatalysts for the Michael reaction of α-branched aldehydes to maleimides. The reaction
α,β-dipeptides as chiralorganocatalysts in the asymmetricMichaeladditionreaction between enolizable aldehydes and N-arylmaleimides or nitroolefins is described. With N-arylmaleimides as substrates, the best results were achieved with dipeptide 2 as a catalyst in the presence of aq. NaOH. Whereas dipeptides 4 and 6 in conjunction with 4-dimethylaminopyridine (DMAP) and thiourea as a hydrogen bond
A highly efficient asymmetric Michael addition of α,α-disubstituted aldehydes to maleimides catalyzed by primary amine thiourea salt
作者:Feng Yu、Zhichao Jin、Huicai Huang、Tingting Ye、Xinmiao Liang、Jinxing Ye
DOI:10.1039/c0ob00154f
日期:——
The first highlyefficientMichaeladdition of challenging α,α-disubstituted aldehydes to maleimides catalyzed by a simple bifunctional primary amine thiourea catalyst/benzoic acid system has been successfully developed to generate quaternary carbon centers in high yields (up to 99%) with excellent enantioselectivities (91–99%).
Highly enantioselective Michael addition of α,α-disubstituted aldehydes to maleimides catalyzed by new primary amine-squaramide bifunctional organocatalysts
作者:Zhi-wei Ma、Xiao-feng Liu、Jun-tao Liu、Zhi-jing Liu、Jing-chao Tao
DOI:10.1016/j.tetlet.2017.10.026
日期:2017.11
amine-squaramides catalyzed asymmetric Michael addition reaction of α,α-disubstituted aldehydes to maleimides has been developed. This organocatalytic asymmetric reaction provides easy access to functionalized succinimides with a broad substrate scope. Both enantiomers of desired succinimide derivatives were obtained in good to excellent yields (up to 98%) with excellent enantioselectivities (up to >99% ee)
Enantioselective Michael addition of α,α-disubstituted aldehydes to maleimides organocatalyzed by chiral primary amine-guanidines
作者:Angel Avila、Rafael Chinchilla、Carmen Nájera
DOI:10.1016/j.tetasy.2012.11.002
日期:2012.12
New primaryamine-guanidines derived from the monoguanylation of (1S,2S)- and (1R,2R)-cyclohexane-1,2-diamine have been prepared and used as chiral organocatalysts for the enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides. The corresponding Michael adducts bearing a new stereocenter were generally obtained in high or quantitative yields and with good enantioselectivities