Highly efficient asymmetric organocatalytic Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated aldehydes.
The development of an improved organocatalyst, N-isopropylated bipyrrolidine 2a, for the asymmetric Friedel-Crafts alkylation of indoles with alpha,beta-unsaturated aldehydes has been presented. The new organocatalyst readily facilitates the enantioselective alkylation reaction, providing 3-alkylated indoles in good to high yields (62-89%) with high levels of enantioselectivity (80-93% ee) using only 2 mol% of catalyst loading.
Jin
Shangbin
S
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Li
Chenguang
C
Ma
Yuanhui
Y
Kan
Yuhe
Y
Zhang
Yong Jian
YJ
Zhang
Wanbin
W