| Abstract |
A series of palladium aminocarbene complexes [PdCl\(C) under bar (N=C((C6RRRRCO)-R-2-R-3-R-4-C-5 (N) under bar))=N(H)R-1\(C NR1)] (9-23, 80-85\% isolated yield) were obtained via the metal-mediated integration of one isonitrile in cis-[PdCl2(C=NR1)(2)] [R-1 = Cy 1, t-Bu 2, Xyl 3, 2-Cl, 6-Me-C6H3 4] and various 3-iminoisoindolin-1-ones [R-2-R-5 = H 5; R-2, R-4, R-5 = H, R-3 = Me/R-2, R-3, R-5 = H, R-4= Me 6 (isomeric mixture); R-2, R-5 = H, R-3, R-4 = Cl 7; R-2-R-5 = F 8]. New compounds 18-23 were completely characterized using (C, H, N), ESI+-MS, IR, 1D (H-1, C-13\H-1\) and 2D (H-1, H-1 COSY, H-1, C-13 HMQC/H-1, C-13 HSQC, H-1, C-13 HMBC) NMR spectroscopies. The efficiency of all prepared aminocarbene species 9-23 in Suzuki-Miyaura cross-coupling reaction of aryl-bromides and iodides was evaluated, showing that complexes 9, 14 and 21 manifest the highest activity furnishing the coupling product in 81-99\% yield, and giving maximum turnover numbers (TONs) up to 7.6 x 10(4). Catalytic system employs non-dried EtOH as an environmentally benign solvent, K2CO3 as a base, and runs under air. (C) 2011 Elsevier B.V. All rights reserved. |
