Redirecting a Diels-Alder Reaction toward (2 + 2)-Cycloaddition

J Org Chem. 2021 Mar 19;86(6):4398-4404. doi: 10.1021/acs.joc.0c02386. Epub 2021 Feb 25.

Abstract

Recently, reactions of allylidenhydrazones with tetracyanoethylene were found to lead to cyclobutanes-products of usually unfavorable (2 + 2) cycloaddition. Herein we computationally demonstrate that the (4 + 2) product of this reaction is severely destabilized by incomplete C-N bond formation, arising from a complex interplay of substituent electronic effects. We show how destabilization of a single bond in the front-runner product averts its formation and redirects chemical reaction toward an uncharacteristic pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cycloaddition Reaction*