Department of Chemistry, University of Leicester, Leicester, UK LE1 7RH.
Dalton Trans. 2010 Nov 21;39(43):10447-57. doi: 10.1039/c0dt00280a. Epub 2010 Oct 6.
The cyclometallated complexes [MCl(C^N)(ring)] (HC^N = 2-phenylpyrazole, M = Ir, Rh ring = Cp*; M = Ru, ring = p-cymene) readily undergo insertion reactions with RC≡CR (R = CO(2)Me, Ph) to give mono insertion products, the rhodium complex also reacts with PhC≡CH regiospecifically to give an analogous product. The products of the reactions of the cyclometallated imine complexes [MCl(C^N)Cp*] (HC^N = PhCH=NR, R = Ph, CH(2)CH(2)OMe, Me; M = Ir, Rh) with PhC≡CPh depend on the substituent R; when R = CH(2)CH(2)OMe a monoinsertion is observed, however for R = Me the initial insertion product is unstable, undergoing reductive elimination with loss of the organic fragment, and for R = Ph no metal-containing product is isolated. With PhC≡CH the cyclometallated imine complexes can give mono or di-insertion products. The implications for catalytic synthesis of carbo- and heterocycles by a tandem C-H activation, alkyne insertion mechanism are discussed.
环金属化配合物 [MCl(C^N)(ring)]（HC^N = 2-苯基吡唑，M = Ir，Rh；ring = Cp*；M = Ru，ring = p-枯烯）容易与 RC≡CR（R = CO(2)Me，Ph）发生插入反应，生成单插入产物，铑配合物也能与 PhC≡CH 特异性地反应，生成类似产物。环金属化亚胺配合物 [MCl(C^N)Cp*]（HC^N = PhCH=NR，R = Ph，CH(2)CH(2)OMe，Me；M = Ir，Rh）与 PhC≡CPh 的反应产物取决于取代基 R；当 R = CH(2)CH(2)OMe 时，观察到单插入，然而对于 R = Me，初始插入产物不稳定，发生还原消除，失去有机片段，对于 R = Ph，没有分离出含有金属的产物。PhC≡CH 可以与环金属化亚胺配合物生成单插入或双插入产物。讨论了通过串联 C-H 活化、炔烃插入机制进行碳环和杂环催化合成的意义。
