20 research outputs found
The Catalytic Asymmetric Knoevenagel Condensation
116 years after the discovery of the Knoevenagel condensation, the first catalytic asymmetric variant has been developed. Dynamic kinetic resolution in the reaction of α‐branched aldehydes with malonates in the presence of a newly designed and readily available modified cinchona amine catalyst gives the corresponding alkylidene malonates in high enantioselectivity (see scheme)
Functionalized Chiral Ionic Liquid Catalyzed Enantioselective Desymmetrizations of Prochiral Ketones via Asymmetric Michael Addition Reaction
N-Pyrrolidine-2-ylmethyl)-2-hydroxy-3-aminopinanes as novel organocatalysts for asymmetric conjugate additions of ketones to α-nitroalkenes
Enantioselective conjugate addition of nitroalkanes to vinyl sulfone: An organocatalytic access to chiral amines
10.1021/ol9003349Organic Letters1181721-172
Mechanistic Rationalization of Organocatalyzed Conjugate Addition of Linear Aldehydes to Nitro-olefins
Kinetic studies of the conjugate addition of propanal to nitrostyrene catalyzed by diarylprolinol ethers reveal that formation of the product iminium species is rate-determining and is promoted by both the reaction product and acid additives. The beneficial role of a dominant cyclobutane intermediate in maintaining high stereoselectivity is highlighted. This mechanistic understanding led to the design of highly productive reaction protocols