On the enantioselective olefin epoxidation by doubly bridged biphenyl azepine derivatives - mixed tropos/atropos chiral biaryls

Diastereomeric doubly bridged biphenyl azepines, atropos at 20 degrees C and tropos at 80 degrees C, are precursors to effective iminium organocatalysts that are employed in the enantioselective epoxidation of prochiral olefins ( up to 85% ee).