Evolution of Pyrrolidine-Type Asymmetric Organocatalysts by “Click” Chemistry
摘要:
[GRAPHICS]Click chemistry has been employed to construct a library of the pyrrolidine-type asymmetric organocatalysts. The clicked organocatalysts were evaluated in asymmetric Michael addition of ketones to nitroolefins, showing good catalytic activity and stereoselectivity (up to 100% yield, syn:anti=99:1, 96% ee).
Influence of steric demand on ruthenium-catalyzed cycloaddition of sterically hindered azides
作者:Venkata S. Sadu、Sirisha Sadu、Seji Kim、In-Taek Hwang、Ki-Jeong Kong、Kee-In Lee
DOI:10.1039/c6ra25403a
日期:——
The RuAAC of sterically hindered 2,2-diaryl-2-azidoamines and terminal alkynes resulted in the unprecedented formation of 1,4-disubstituted-1,2,3-triazoles. A control experiment with 2-(azidomethyl)pyrrolidine revealed the usual selectivity with RuAAC and the reactions of azides with intermediate bulkiness gave mixtures of 1,4- and 1,5-regioisomers. The results suggest that the steric demands could