N,N′-Dialkylation Catalyzed by Bimetallic Iridium Complexes Containing a Saturated Bis-N-Heterocyclic Carbene (NHC) Ligand
作者:Hsin-Ya Kuo、Yi-Hong Liu、Shie-Ming Peng、Shiuh-Tzung Liu
DOI:10.1021/om300800c
日期:2012.10.22
Reaction of the bis-aminophosphinimine [m-C6H4(HNCH2CH2N═PPh3)] with W(CO)6 afforded [m-C6H4(CNCH2CH2NH)W(CO)5}2] (2), which underwent N-alkylation with benzyl bromide to yield [m-C6H4(CNCH2CH2NCH2Ph)W(CO)5}2] (3). A carbene transfer reaction from W(0) to Ir(I) proceeded smoothly via the reaction of 3 with [Ir(COD)Cl]2 under mild conditions to give the diiridium(I) carbene complex [m-C6H4(CNCH2CH2NH)Ir(CO)2Cl}2]
双氨基膦亚胺[ m -C 6 H 4(HNCH 2 CH 2 N = PPh 3)]与W(CO)6反应,得到[ m -C 6 H 4 (CNCH 2 CH 2 NH)W(CO)5 } 2 ](2),将其与苄基溴进行N-烷基化反应,得到[ m -C 6 H 4 (CNCH 2 CH 2 NCH 2 Ph)W(CO)5 } 2 ](3)。通过3与[Ir(COD)Cl] 2的反应,在温和的条件下,从W(0)到Ir(I)的卡宾转移反应顺利进行,得到二铱(I)卡宾络合物[ m -C 6 H 4 (CNCH 2 CH 2 NH)Ir(CO)2 Cl} 2 ](4)。用过量的PPh 3进行配体4的取代,生成了膦配合物5。所有配合物均已通过光谱和元素分析进行了表征。配合物2和5通过X射线衍射研究进一步证实。复杂的图4是用于苯二胺与醇的还原性N,N'-二烷基化的有效催化剂。讨论了涉及两个金属中心之间可能协同作用的催化机理。