Photocatalytic [2 + 2] cycloadditions of enones with cleavable redox auxiliaries.
α,β-Unsaturated 2-imidazolyl ketones undergo [2 + 2] cycloaddition with a variety of Michael acceptors upon irradiation with visible light in the presence of Ru(bpy)(3)(2+). Cleavage of the imidazolyl auxiliary from the cycloadducts affords cyclobutane carboxamides, esters, thioesters, and acids that would not be accessible from direct cycloaddition of the corresponding unsaturated carbonyl compounds.
Department of Chemsitry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
Elizabeth L
EL
Tyson
Elliot P
EP
Farney
Tehshik P
TP
Yoon
D002384:Catalysis; D003500:Cyclization; D019281:Dimerization; D015394:Molecular Structure; D010084:Oxidation-Reduction; D055668:Photochemical Processes