铱PCP夹杂物对水的氧化加成反应:IrH(OH){C 6 H 3 -2,6-(CH 2 PBu t 2)2 }对烷烃的催化脱氢
摘要:
叔丁基乙烯对IrH 2 {C 6 H 3 -2,6-(CH 2 PBu t 2)2 }(1)进行脱氢,然后与过量的水反应导致IrH(OH){C的分离6 H 3 -2,6-(CH 2 PBu t 2)2 }(2)几乎是定量的。氢化物羟基络合物已通过多核NMR光谱法以及单晶X射线结构测定进行了表征。用D 2 O进行的同位素标记研究表明2由水氧化到中间的14电子配合物Ir {C 6 H 3 -2,6-(CH 2 PBu t 2)2 }中引起。标题配合物是用于将环辛烷转移脱氢为环辛烯的有效催化剂,但是对烷烃被水羟基化没有显示催化活性。通过将2的溶液置于25°C下的1 atm H 2下,可以逆转1到2的转化。
Catalytic Dehydrogenation of Alkanes by PCP–Pincer Iridium Complexes Using Proton and Electron Acceptors
作者:Arun Dixith Reddy Shada、Alexander J. M. Miller、Thomas J. Emge、Alan S. Goldman
DOI:10.1021/acscatal.0c05160
日期:2021.3.5
alkane dehydrogenation by proton-coupled electron transfer, using pairs of oxidants and bases as proton and electron acceptors. Up to 97% yield was achieved with respect to oxidant and base, and up to 15 catalytic turnovers with respect to iridium, using t-butoxide as base coupled with various oxidants, including oxidants with very low reduction potentials. Mechanistic studies indicate that (pincer)IrH2
Selective Cleavage of the C−C Bonds of Aminoethyl Groups, via a Multistep Pathway, by a Pincer Iridium Complex
作者:Xiawei Zhang、Thomas J. Emge、Rajshekhar Ghosh、Alan S. Goldman
DOI:10.1021/ja051300p
日期:2005.6.1
A pincer-ligated iridiumcomplex is found to react with N-ethylamines, HN(Et)R (R = cyclohexyl, tert-butyl, ethyl), to give the corresponding iridium isocyanide complexes (PCP)Ir(CH3)(H)(CNR) (PCP = kappa3-2,6-(tBu2PCH2)2C6H3). This novel, regioselective C-C bond cleavage reaction occurs readily under mild conditions (25-45 degrees C). The reaction is shown to proceed via initial dehydrogenation of
Distinct Thermodynamics for the Formation and Cleavage of N−H Bonds in Aniline and Ammonia. Directly-Observed Reductive Elimination of Ammonia from an Isolated Amido Hydride Complex
作者:Mira Kanzelberger、Xiawei Zhang、Thomas J. Emge、Alan S. Goldman、Jing Zhao、Christopher Incarvito、John F. Hartwig
DOI:10.1021/ja037363u
日期:2003.11.1
form the ammonia complex 2. Addition of CO to anilide complex 1a gave (PCP)Ir(PhNH)(H)(CO) (4a). Addition of CNtBu to terminalamidocomplex 1b formed (PCP)Ir(NH2)(H)(CNtBu) (4b), the first structurally characterized iridiumamido hydride. Complexes 4a and 4b underwent reductive elimination of aniline and ammonia; parent amidocomplex 4b reacted faster than anilide 4a. These observations suggest distinct
Protonation and electrochemical reduction of rhodium– and iridium–dinitrogen complexes in organic solution
作者:Gannon P. Connor、Nicholas Lease、Andrea Casuras、Alan S. Goldman、Patrick L. Holland、James M. Mayer
DOI:10.1039/c7dt03476h
日期:——
Protonation and reduction of pincer-ligated Rh– and Ir–N2 complexes have been studied by NMR spectroscopy and cyclic voltammetry to assess the capability of these complexes to activate or reduce N2. Protonation, which is a prerequisite to electrochemicalreduction, results in a cationic metal-hydride that loses N2 under an atmosphere of Ar. Reduction of the metal-hydride results in fast disproportionation
Dehydrogenation of <i>n</i>-Alkanes Catalyzed by Iridium “Pincer” Complexes: Regioselective Formation of α-Olefins
作者:Fuchen Liu、Esther B. Pak、Bharat Singh、Craig M. Jensen、Alan S. Goldman
DOI:10.1021/ja983460p
日期:1999.4.1
n-alkanes to the corresponding 1-alkenes (alpha}-olefins) since these serve as precursors for a wide range of commodity-scale chemicals (>2 times} 10sup 9} kg/yr). Such a conversion is also an intriguing challenge as viewed from a fundamental perspective. n-Alkanes are the simplest organic molecules with the potential to undergo regioselective transformations; alpha}-olefins are the thermodynamically least