Organocatalytic asymmetric direct vinylogous Michael addition of α,β-unsaturated γ-butyrolactam to nitroolefins
作者:Abhijnan Ray Choudhury、Santanu Mukherjee
DOI:10.1039/c2ob25832c
日期:——
The first organocatalytic enantioselective directvinylogousMichael reaction of α,β-unsaturatedγ-butyrolactam to nitroolefins is developed using cinchona alkaloids as the catalysts. Both product enantiomers are accessible with moderate to good enantioselectivity.
The present invention provides a (meth)acrylate manufacturing method characterized in that when manufacturing a (meth) acrylate by an ester exchange reaction between an alcohol and a monofunctional (meth)acrylate using catalyst A and catalyst B together, contact treatment of the ester exchange reaction product with adsorbent C is performed. Catalyst A: One or more kinds of compounds selected from a group consisting of cyclic tertiary amines with an azabicyclo structure and salts or complexes thereof, amidine and salts or complexes thereof, compounds with a pyridine ring and salts or complexes thereof, phosphines and salts or complexes thereof, and compounds with a tertiary diamine structure and salts or complexes thereof. Catalyst B: One or more kinds of compounds selected from a group consisting of compounds comprising zinc. Adsorbent C: One or more kinds of compounds selected from a group consisting of oxides and hydroxides comprising at least one of magnesium, aluminum and silicon.
A method for producing a (meth) acrylate comprises transesterification reaction of an alcohol and a monofunctional (meth) acrylate with catalysts in combination being cyclic tertiary amines having an azabicyclo structure and compounds containing zinc, separating a solid that contains the catalysts from a reaction product containing a (meth) acrylate, and producing a (meth) acrylate by transesterification reaction of an alcohol and a monofunctional (meth) acrylate, while using the recovered solid catalyst.
Asymmetric oxaziridination catalyzed by cinchona alkaloid derivatives containing sulfide
作者:Tianyi Zhang、Wei He、Xingyu Zhao、Ying Jin
DOI:10.1016/j.tet.2013.06.061
日期:2013.9
A newmethod has been developed for the asymmetric oxaziridination of aryl aldimines with m-chloroperbenzoic acid, involving the use of cinchonaalkaloid derivatives containing a sulfide moiety as a catalyst. The newmethod provided access to optically active oxaziridines in good yields with high enantiomeric excess (ee) values of up to 95%.
Cinchonidinium acetate as a convenient catalyst for the asymmetric synthesis of cis-stilbenediamines
作者:Ryan R. Walvoord、Marisa C. Kozlowski
DOI:10.1016/j.tetlet.2014.12.105
日期:2015.6
Inexpensive and readily available cinchonidinium acetate is an effective catalyst for the syn-selective aza-Henry reaction of arylnitromethanes and aryl imines. The resulting masked cis-stilbenediamine products are produced in excellent diastereoselectivity and good enantioselectivity, and enantiopure material can be achieved via recrystallization. The features of the cinchona catalyst needed for selectivity