A Chiral Thiourea as a Template for Enantioselective Intramolecular [2 + 2] Photocycloaddition Reactions

J Org Chem. 2016 Aug 19;81(16):6965-71. doi: 10.1021/acs.joc.6b01039. Epub 2016 Jun 9.

Abstract

A chiral (1R,2R)-diaminocyclohexane-derived bisthiourea was found to exhibit a significant asymmetric induction in the intramolecular [2 + 2] photocycloaddition of 2,3-dihydropyridone-5-carboxylates. Under optimized conditions, the reaction was performed with visible light employing 10 mol % of thioxanthone as triplet sensitizer. Due to the different electronic properties of its carbonyl oxygen atoms, a directed binding of the substrate to the template is possible, which in turn enables an efficient enantioface differentiation.

Publication types

  • Research Support, Non-U.S. Gov't