Enantioselective Oxazaborolidinium‐Catalyzed Diels–Alder Reactions without CH⋅⋅⋅⋅O Hydrogen Bonding

Abstract

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. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z802002_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.