Enantioselective oxazaborolidinium-catalyzed Diels - Alder reactions without CH....O hydrogen bonding

Abstract

(Chemical Equation Presented) All cis-tems go! The first detailed computational investigations into the title reaction validate Corey's two pre-transition-state models and reveal a third Lewis acid coordination mode (see picture), which operates for esters having s-cis C=C-C=O groups. The new pre-transition-state model explains the unexpected enantioselectivity witnessed for several Diels-Alder reactions and does not involve a C-H⋯O hydrogen bond. Show more