Synthesis of neutral nickel–methyl complexes with monodentate imines and their sequential insertion of carbon monoxide and imine
摘要:
Neutral nickel-imine complexes of the form (N boolean AND O)Ni(R)((RN)-N-1=C(H)R-2) (N boolean AND O = salicylaldiminato; R = CH3, Ph; R-1 = alkyl; R-2 = aryl) can be prepared by the reaction of (tmeda)Ni(CH3)(2), imine and the corresponding salicylaldiminato ligand. The addition of carbon monoxide to these complexes lead to the in situ generation of the corresponding nickel-acyl complexes. With N-methyl or N-benzyl substituted imines, these complexes reductively eliminate the phenolic and acyl ligands to generate esters. However, the less sterically encumbered 3,4-dihydroisoquinoline can couple with the nickel-acyl ligand to form 1,2-diamides in high yield. In situ H-1 NMR analysis suggests this reaction occurs via insertion of imine into the nickel-acyl bond to form a nickel-bound amide complex.[GRAPHICS](C) 2010 Elsevier B. V. All rights reserved.
Synthesis of neutral nickel catalysts for ethylene polymerization ? the influence of ligand size on catalyst stabilityElectronic supplementary information (ESI) available: experimental protocol for (tmeda)Ni(Me)2 and compounds 3,4,7,8,9 and 10 and 1H-NMR magnetization transfer data for compound 7. See http://www.rsc.org/suppdata/cc/b3/b306701g/
作者:Eric F. Connor、Todd R. Younkin、Jason I. Henderson、Andrew W. Waltman、Robert H. Grubbs
DOI:10.1039/b306701g
日期:——
A facile synthesis of nickel salicylaldimine complexes with labile dissociating ligands is described. In addition to producing highly active ethylene polymerization catalysts, important insights into the effect of ligand size on catalyst stability and information on the mechanism of polymerization are provided.