Organocatalytic regioselective asymmetric Michael addition of azlactones to o-hydroxy chalcone derivatives
作者:Shao-Yun Zhang、Gui-Yu Ruan、Zhi-Cong Geng、Nai-Kai Li、Ming Lv、Yong Wang、Xing-Wang Wang
DOI:10.1039/c5ob00121h
日期:——
enantioselective Michaeladdition between azlactones and o-hydroxy chalcone derivatives is reported. Enantiomerically enriched N,O-aminals with two continuous stereogenic centers are exclusively obtained in moderate to good yields with excellent diastereoselectivities and good to excellent enantioselectivities. The experimental results show that an o-hydroxy group on the cinnamenyl motif of chalcone derivatives
A simple and convenient method towards the synthesis of highly diversified chromenopyrazole/indoline frameworks in excellent yields via iodine promoted triple dominoreaction involving Michael addition followed by intramolecular cyclization and dehydrogenation sequence has been described for the first time.