Bidentate Lewis acids, by virtue of having two metallic centers, possess the ability to coordinate cooperatively to multidentate ligands and increase the organizational role of the Lewis acid in the transition state.  One acidic site can organize a ligand while the second site activates a substrate.  The modification of 1,8-naphthalenediylbis (dichloroborane) with chiral ligands derived from non-racemic diols and natural amino acids results in the formation of chiral bidentate Lewis acids which show activity in the Diels-Alder reaction with α,β-unsaturated aldehyde dienophiles and cyclopentadiene.  Enantioselectivities as high as 62% for the major diastereomeric adduct and 99% for the minor diastereomeric adducts have been achieved to date.