- exo-Selective construction of spiro-[butyrolactone-pyrrolidine] via 1,3-dipolar cycloaddition of azomethine ylides with α-methylene-γ-butyrolactone catalyzed by Cu(I)/DTBM-BIPHEP.
exo-Selective construction of spiro-[butyrolactone-pyrrolidine] via 1,3-dipolar cycloaddition of azomethine ylides with α-methylene-γ-butyrolactone catalyzed by Cu(I)/DTBM-BIPHEP.
Chemical communications (Cambridge, England) (2013-09-12)
Qing-Hua Li, Tang-Lin Liu, Liang Wei, Xiang Zhou, Hai-Yan Tao, Chun-Jiang Wang
PMID24022250
ABSTRACT
An expedient access to optically active spiro-[butyrolactone-pyrrolidine] was successfully developed via an unprecedented Cu(I)-catalyzed exo-selective 1,3-DC of azomethine ylides with α-methylene-γ-butyrolactone, which exhibited high diastereoselectivity (>98 : 2), excellent enantioselectivity (96->99% ee) and a broad substrate scope under mild conditions.
MATERIALS