Department of Chemsitry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
Org Lett. 2012 Feb 17;14(4):1110-3. doi: 10.1021/ol3000298. Epub 2012 Feb 9.
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.
α,β-不饱和 2-咪唑基酮在可见光照射下,在 Ru(bpy)(3)(2+)存在的条件下与各种迈克尔受体发生[2 + 2]环加成反应。从环加成产物中脱除咪唑基辅助基可得到环丁烷羧酰胺、酯、硫酯和酸,这些化合物无法通过相应的不饱和羰基化合物的直接环加成得到。