| Abstract |
Aminocarbene complexes cis-[PtCl2\C(N(H)N = (CRR3)-R-2)=N(H)R-1)(CNR1)] (7-15) prepared via the nucleophilic addition of hydrazones H2N-N=CR2123 [R-2, R-3 = Ph 4; R-2/123 = 9H-fluorenyl 5; R-2 = H, R-3 = 2-(OH)C6H4 6] to cis-[PtCl2(CNR1)2] [R1 = cyclohexyl (Cy) 1, 2,6-Me2C6H3 (Xyl) 2, 2-CI-6-MeC(6)H(3)3] were evaluated as catalysts for the hydrosilylation of terminal allcynes with trisubstituted silanes giving vinyl silanes. The optimized catalytic system runs at 80-100 degrees C in dry toluene for 3-6 h with a typical catalyst loading of 0.1 mol\%. A range of substrates with different steric hindrance and activity (Et3SiH, Pr3SiH, (Pr3SiH)-Pr-i, and PhMe2SiH as silanes; PhC CH, (BuC)-Bu-t CH, and 4-(Bu-t)C6H4 CH as allcynes) were successfully transformed into the target silylated products in 83-99\% yields attesting the versatility of our catalytic system. Decreasing the catalysts loading to 10-3 mol\% guaranteed the maximum TONs of 4.0 x 10(4) and TOFs of 1.7 x 10(2) (h(-1)) that were accomplished within 24 h of the reaction. (C) 2013 Elsevier Inc. All rights reserved. |
