Ischay Michael A, Ament Michael S, Yoon Tehshik P
Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706, USA.
Chem Sci. 2012;3(9):2807-2811. doi: 10.1039/C2SC20658G. Epub 2012 Jun 25.
We report a method for the crossed [2+2] cycloaddition of styrenes using visible light photocatalysis. Few methods for the synthesis of unsymmetrically substituted cyclobutanes by photochemical [2+2] cycloaddition are known. We show that careful tuning of the electrochemical properties of a ruthenium photocatalyst enable the efficient crossed [2+2] cycloaddition of styrenes upon irradiation with visible light. We outline the logic that enables high crossed chemoselectivity, and we also demonstrate that this reaction is remarkably efficient; gram-scale reactions can be conducted with as little as 0.025 mol% of the photocatalyst.
我们报道了一种利用可见光光催化实现苯乙烯交叉[2+2]环加成的方法。通过光化学[2+2]环加成合成不对称取代环丁烷的方法很少。我们表明，对钌光催化剂的电化学性质进行精细调节，能够在可见光照射下实现苯乙烯的高效交叉[2+2]环加成。我们概述了实现高交叉化学选择性的逻辑，并且还证明了该反应非常高效；使用低至0.025 mol%的光催化剂即可进行克级规模的反应。
