A group of chiral [(salen)Cr(III)] + BF 4 - complexes, with enhanced steric hindrance in 3,3'-positions of salicylidene moiety, has been synthesized and applied for the oxo-Diels-Alder reaction of alkyl glyoxylates with cyclohexa-1,3-diene. A readilyaccessiblecomplex that bears bulky adamanthyl substituents revealed its potential, leading to the cycloadducts with excellent selectivity (up to endolexo