Functionalized cyclobutenes via multicomponent thermal [2 + 2] cycloaddition reactions.
[reaction: see text] Enamine [2 + 2] cycloadditions can be achieved in useful yields simply by stirring a mixture of an aldehyde, diethylamine, a dialkyl fumarate, and potassium carbonate in acetonitrile at 25 degrees C, conditions that are compatible with the presence of a potential leaving group on the beta-position of the intermediate enamine. Methylation and elimination of the product cyclobutanes completes a mild nonphotochemical route to functionalized cyclobutenes.
Sheldrake
Helen M
HM
School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Wallace
Timothy W
TW
Wilson
Craig P
CP