Triflimide Activation of a Chiral Oxazaborolidine Leads to a More General Catalytic System for Enantioselective Diels−Alder Addition
作者:Do Hyun Ryu、E. J. Corey
DOI:10.1021/ja035393r
日期:2003.5.1
The strong acid triflimide ((CF3SO2)2NH) protonates chiral oxazaborolidines to form superactive, stable, chiral Lewis acids which are highly effective catalysts for a wide variety of enantioselective Diels-Alder reactions, documented herein by more than 20 examples.
Chiral Oxazaborolidine−Aluminum Bromide Complexes Are Unusually Powerful and Effective Catalysts for Enantioselective Diels−Alder Reactions
作者:Duan Liu、Eda Canales、E. J. Corey
DOI:10.1021/ja068637r
日期:2007.2.1
acid catalyst than protonated 1 (i.e., 2) for enantioselectiveDiels−Alderreactions. Only 4 mol % of catalyst 3 is required to achieve yields and enantiomeric purities of 90% over a broad range of achiraldienes and dienophiles. The ligand from which 3 is derived can be recovered easily and with high efficiency. The method is illustrated by 22 examples.