Catalytic Asymmetric Mannich-Ketalization Reaction: Highly Enantioselective Synthesis of Aminobenzopyrans
作者:Magnus Rueping、Ming-Yuan Lin
DOI:10.1002/chem.201000203
日期:2010.4.12
Domino catalysis: We have developed the first enantioselective domino Mannich–ketalization reaction of o‐hydroxy benzaldimines with electron‐rich alkenes (see scheme). The new reaction sequence provides an easy and direct access to optically pure 4‐aminobenzopyrans in good yields and with excellent enantiomeric ratios (up to e.r. 98:2).