1376532-22-7Relevant academic research and scientific papers
Hybrid NCS palladium pincer complexes of thiophosphorylated benzaldimines and their ketimine analogs
Aleksanyan, Diana V.,Kozlov, Vladimir A.,Shevchenko, Nikolay E.,Nenajdenko, Valentine G.,Vasil'ev, Andrei A.,et al.
, p. 52 - 61 (2012/08/14)
A series of novel hybrid pincer ligands bearing thiophosphoryl and iminogroups as donating arms was obtained by the condensation of 3- diphenyl thiophosphorylbenzaldehyde with RNH2 (R = Ph, tBu)to afford aldimine derivatives 2a, b or by the reaction of lithiated 3- (thiophosphoryl)bromobenzene with an appropriate substituted lactam yielding their ketimine analogs 2c-e with 5-7-membered azacycloalkene moieties. The direct cyclopalladation of the ligands with (PhCN)2PdCl2 in MeCN under reflux led to κ3-NCS pincer complexes 3b-e with two five-membered fused metallacycles, isolated inlow to moderate yields (12-53percent); their structures were confirmed by multinuclear NMR and X-ray diffraction study. The palladacycles demon strated high activity as (pre)catalysts for the Suzuki cross-coupling ofphenylboronic acid with aryl bromides, which was found to increase in t he series 3e ～ 3d 3c 3b, i.e. passing from ketimine derivatives 3d, e with larger azacycloalkene to their analog with smaller five-membered cyclic imine moiety and further to benzaldimine complex 3b. The tendency observed was explained by the controlled release of Pd(0) catalytically active species in the case of less sterically hindered complexes.
