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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Photocatalytic [2 + 2] cycloadditions of enones with cleavable redox auxiliaries
Elizabeth L Tyson1, Elliot P Farney, Tehshik P Yoon
1Department of Chemsitry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
Abstract:
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.
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