Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138 (USA), Fax: (+1)?617‐495‐0376
Abstract:
Chiral oxazaborolidines can be activated by N‐protonation using strong protic acids or by N‐coordination with AlBr3 to form very strong chiral Lewis acids. The resulting chiral boron electrophiles (see structure) are powerful chiral catalysts that effectively promote 4+2], 3+2], and 2+2]‐cycloaddition reactions with high enantioselectivity.
