Efficient Visible Light Photocatalysis of [2+2] Enone Cycloadditions

作者：Michael A. Ischay, Mary E. Anzovino, Juana Du, Tehshik P. Yoon · 发表于：Journal of the American Chemical Society · 年份：2008 · DOI：10.1021/ja805387f · 被引用次数：1150 · 研究领域：Radical Photochemical Reactions、Catalytic C–H Functionalization Methods、CO2 Reduction Techniques and Catalysts

We report that Ru(bipy)3Cl2 can serve as a visible light photocatalyst for [2+2] enone cycloadditions. A variety of aryl enones participate readily in the reaction, and the diastereoselectivity in the formation of the cyclobutane products is excellent. We propose a mechanism in which a photogenerated Ru(bipy)3+ complex promotes one-electron reduction of the enone substrate, which undergoes subsequent radical anion cycloaddition. The efficiency of this process is extremely high, which allows rapid, high-yielding [2+2] cyclizations to be conducted using incident sunlight as the only source of irradiation.