Osmium(0)-Catalyzed C–C Coupling of Ethylene and α-Olefins with Diols, Ketols, or Hydroxy Esters via Transfer Hydrogenation
作者:Boyoung Y. Park、Tom Luong、Hiroki Sato、Michael J. Krische
DOI:10.1021/acs.joc.6b01923
日期:2016.9.16
regioisomers. The collective data, including deuterium labeling studies, are consistent with a catalytic mechanism involving olefin–dione oxidative coupling to form an oxa-osmacyclopentane, which upon reductive cleavage via hydrogen transfer from the secondary alcohol reactant releases the product of carbinol C-alkylation with regeneration of the ketone. Single-crystal X-ray diffraction data of the
衍生自Os 3(CO)12和XPhos(2-二环己基膦基-2',4',6'-三异丙基联苯)的(0)络合物催化α-羟基酯1a - 1i,α-酮醇1j的C-C偶联- 1O,或1,2-二醇二氢- 1J - 1O与乙烯2A以形成乙基叔醇3A - 10-30。如1-辛烯2b与附近的双加氧反应物1a,1b,1i,1j,1k的偶联所示,1m,具有完全水平的支链区域选择性的高级α-烯烃被转化为加合物4a,4b,4i,4j,4k,4m。氧化水平无关的C-C耦合是通过的反应表现出1-辛烯2B与二醇二氢- 1K,α酮醇1K,和二酮脱氢- 1K。功能化的烯烃2c - 2f与扁桃酸乙酯1a反应生成加合物5a - 8a作为单一的区域异构体。包括氘标记研究在内的集体数据与涉及烯烃-二酮氧化偶合形成氧杂-Osmacyclopentane的催化机制相一致,该氧杂-Osmacyclopentpentane在通过仲醇反应物上的