Highly Selective Intramolecular Carbene Insertion into Primary C–H Bond of α-Diazoacetamides Mediated by a (<i>p</i>-Cymene)ruthenium(II) Carboxylate Complex
作者:Vanessa Kar-Yan Lo、Zhen Guo、Matthew Kwok-Wai Choi、Wing-Yiu Yu、Jie-Sheng Huang、Chi-Ming Che
DOI:10.1021/ja3006989
日期:2012.5.9
Complex [(p-cymene)Ru(η(1)-O(2)CCF(3))(2)(OH(2))] mediated transformation of α-diazoacetamides ArCH(2)N(C(CH(3))(3))C(O)CHN(2) to result in carbene insertion into the primary C-Hbond exclusively, with the γ-lactam products being isolated in up to 98% yield. This unexpected reaction is striking in view of the presence of usually more reactive sites such as secondary C-H bonds in the substrates. DFT
amide carbeneinsertion into C–H bonds, yielding γ-lactams with 91% ee in up to 99% yield. This reaction uses a ruthenium(II) phenyl oxazoline (Ru(II)-Pheox) complex. The catalytic intramolecular carbenetransferreaction to the primary C–H bond proceeds rapidly and selectively compared to that with secondary C–H, benzylic secondary C–H, tert-C–H, or sp2C–H bonds in the presence of 1 mol % Ru(II)-Pheox