Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O2
Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O2
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DOI：
10.1021/jacs.5b03956
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发表时间：
2015-07-01
影响因子：
15
通讯作者：
Xiao, Jianliang
中科院分区：
文献类型：
--
作者：
Gonzalez-de-Castro, Angela;Xiao, Jianliang
一个温和的和操作简单的铁催化方案选择性有氧氧化芳烃羰基化合物的描述。在1 atm O-2下，由含吡啶双咪唑啉配体的Fe（III）催化，α -取代苯乙烯和β -取代苯乙烯通常以高收率裂解生成苯甲醛和芳香酮，具有优异的化学选择性和非常好的官能团耐受性，包括那些含有自由基敏感基团的基团。与-halo取代苯乙烯，氧化发生伴随卤化物迁移得到-halo苯乙酮。人们进行了各种各样的观察，指出了一种机制，在这种机制中，分子氧和烯烃底物都配位到铁中心，导致形成二氧烷中间体，中间体坍塌生成羰基产物。
A mild and operationally simple iron-catalyzed protocol for the selective aerobic oxidation of aromatic olefins to carbonyl compounds is described. Catalyzed by a Fe(III) species bearing a pyridine bisimidazoline ligand at 1 atm of O-2, alpha- and beta-substituted styrenes were cleaved to afford benzaldehydes and aromatic ketones generally in high yields with excellent chemoselectivity and very good functional group tolerance, including those containing radical-sensitive groups. With alpha-halo-substituted styrenes, the oxidation took place with concomitant halide migration to afford alpha-halo acetophenones. Various observations have been made, pointing to a mechanism in which both molecular oxygen and the olefinic substrate coordinate to the iron center, leading to the formation of a dioxetane intermediate, which collapses to give the carbonyl product.