铱双（亚膦酸酯）对-XPCP钳形配合物：用于烷烃转移脱氢的高活性催化剂。
Iridium bis(phosphinite) p-XPCP pincer complexes: highly active catalysts for the transfer dehydrogenation of alkanes.
作者信息
Göttker-Schnetmann Inigo, White Peter, Brookhart Maurice
机构信息
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290, USA.
出版信息
J Am Chem Soc. 2004 Feb 18;126(6):1804-11. doi: 10.1021/ja0385235.
A series of new bis(phosphinite) p-XPCPIrHCl pincer complexes ([PCP = eta(3)-5-X-C(6)H(2)OP(tBu)(2)-1,3], X = MeO (4a), Me (4b), H (4c), F (4d), C(6)F(5) (4e), and Ar(F) [=3,5-bis(trifluoromethyl)phenyl] (4f)) have been synthesized. Treatment of compounds 4a-f with NatOBu in cyclooctane (COA)/tert-butylethylene (TBE) mixtures generates species with unprecedented catalytic activity for the catalyzed transfer dehydrogenation of COA with TBE as acceptor to form cyclooctene (COE) and tert-butylethane (TBA). With substrate:precatalyst ratios of 3030COA:3030TBE:1p-XPCPIrHCl (4):1.1NaOtBu, turnover numbers (TONs) between 1400 and 2200 (up to 72% conversion in TBE) and initial turnover frequencies (TOFs) between 1.6 and 2.4 s(-1) have been observed at 200 degrees C.
已合成了一系列新型双（亚膦酸酯）对-XPCPIrHCl钳形配合物（[PCP = η(3)-5-X-C6H2[OP(tBu)2]2-1,3]，X = 甲氧基（4a）、甲基（4b）、氢（4c）、氟（4d）、五氟苯基（4e）和Ar(F) [=3,5-双（三氟甲基）苯基]（4f））。在环辛烷（COA）/叔丁基乙烯（TBE）混合物中用叔丁醇钠处理化合物4a - f，可生成对COA与TBE作为受体进行催化转移脱氢反应以形成环辛烯（COE）和叔丁基乙烷（TBA）具有前所未有的催化活性的物种。在底物：预催化剂比例为3030COA:3030TBE:1对-XPCPIrHCl（4）:1.1叔丁醇钠的情况下，在200℃观察到周转数（TONs）在1400至2200之间（TBE中转化率高达72%），初始周转频率（TOFs）在1.6至2.4 s-1之间。
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