Boron‐Based Enantiomerism
Manfred Braun
Abstract
Abstract Boron‐based enantiomerism is fragile due to the inherent tendency of a dissociation of a ligand from tetra‐coordinate chiral boron complexes under formation of the achiral tri‐coordinate species. This review will present the different approaches in overcoming the inherent tendency of racemization in boron‐stereogenic compounds. When embedded in an environment of chiral ligands or substituents, configurationally stable boron stereogenic centers can form in a diastereoselective manner. Compounds incorporating boron as the exclusive stereogenic center are obtained by resolution of the racemic mixtures. The recently developed – much more efficient – methods of a catalytic, enantioselective creation of boron stereogenic compounds are highlighted in this review. Finally the chiroptical properties of enantiomerically pure boron complexes that makes them promising materials or devices are addressed.