N-heterocyclic carbene catalyzed transformations of 3-halopropenals to the equivalents of beta-acylvinyl anions.
3-Halopropenals 1 can behave as an alternative equivalent of beta-acylvinyl anions (I) in the presence of N-heterocyclic carbene precursor (IPr.HCl) and DBU to afford cyclic alpha,beta-unsaturated carbonyl derivatives, butenolides 4 and pyrazolone 6, after cyclization with 2 and 5, respectively.
Wu
Yihua
Y
Department of Chemistry, Zhejiang University, 20 Yugu Road, Hangzhou 310027, People's Republic of China.
Yao
Weijun
W
Pan
Lianjie
L
Zhang
Yiping
Y
Ma
Cheng
C