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.
Catalytic enantioselective Diels–Alder reactions of furans and 1,1,1-trifluoroethyl acrylate
作者:Do Hyun Ryu、Kyung Hwa Kim、Jae Yi Sim、E.J. Corey
DOI:10.1016/j.tetlet.2007.06.097
日期:2007.8
CatalyticenantioselectiveDiels–Alderreactions of furans and 1,1,1-trifluoroethyl acrylate in the presence of oxazaborolidium catalysts 2 or 3 provide 7-oxabicyclo[2.2.1]hept-5-enes with high endo-selectivity and excellent enantioselectivity.