Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53705, USA.
J Am Chem Soc. 2009 Oct 21;131(41):14604-5. doi: 10.1021/ja903732v.
Efficient [2+2] heterodimerizations of dissimilar acyclic enones can be accomplished upon visible light irradiation in the presence of a ruthenium(II) photocatalyst. Similar cycloadditions under standard UV photolysis conditions are inefficient and unselective. Nevertheless, a diverse range of unsymmetrical tri- and tetrasubstituted cyclobutane structures can be produced in good yields and excellent diastereoselectivities using this new method. The reaction is promoted by any visible light source, and efficient, gram-scale cycloadditions can be conducted upon irradiating with ambient sunlight.
在钌(II)光催化剂的存在下,通过可见光照射可以高效地完成不同非环状烯酮的[2+2]杂二聚反应。而在标准的紫外光解条件下,相似的环加成反应效率低且无选择性。尽管如此,使用这种新方法可以以良好的收率和优异的非对映选择性得到各种不同的非对称三取代和四取代的环丁烷结构。该反应可被任何可见光光源促进,并且可以在照射环境阳光时进行高效、克级规模的环加成反应。