TY - JOUR
T1 - Insertion reactions of unsymmetrical ester-activated alkynes with o-benzylamine palladacycles
T2 - A regioselectivity study
AU - Kelly, Amy E.
AU - Macgregor, Stuart A.
AU - Willis, Anthony C.
AU - Nelson, John H.
AU - Wenger, Eric
PY - 2003/8/6
Y1 - 2003/8/6
N2 - The regioselectivities of the insertion reactions of RC=CCO2Et (R=Ph, CF3) into the aryl-palladium bond of several five-membered, ortho-palladated dimethylbenzylamine complexes, [PdCl(C6H4CH2NMe2-?C,N)] 2 (1), [PdCl(C6H4CH2NMe2-?C,N)(L)] [L=PEt3 (2), DMPP (3)], [Pd(C6H4CH2NMe2-?C,N) (NCMe)(L)]PF6 [L=MeCN (4), PEt3 (9), DMPP (5)], [Pd(OSO2CF3)(C6H4CH 2NMe2-?C,N)(DMPP)] (6), [Pd(C6H4CH2NMe2-?C,N) (solvent)]PF6 (7) and [Pd(C6H4CH2NMe2-?C,N) (DMPP)(solvent)]PF6 (8), have been compared with the help of multinuclear NMR spectroscopy. In general, the carboxylate group in the resulting seven-membered palladacycles is preferentially located next to the phenyl group of the benzylamine moiety, but this substitution pattern can be reversed by use of complexes containing electron-deficient and/or coordinatively-unsaturated palladium centres. A mechanism, based both on the experimental results described in this paper and on DFT computations, is proposed. © 2003 Elsevier Science B.V. All rights reserved.
AB - The regioselectivities of the insertion reactions of RC=CCO2Et (R=Ph, CF3) into the aryl-palladium bond of several five-membered, ortho-palladated dimethylbenzylamine complexes, [PdCl(C6H4CH2NMe2-?C,N)] 2 (1), [PdCl(C6H4CH2NMe2-?C,N)(L)] [L=PEt3 (2), DMPP (3)], [Pd(C6H4CH2NMe2-?C,N) (NCMe)(L)]PF6 [L=MeCN (4), PEt3 (9), DMPP (5)], [Pd(OSO2CF3)(C6H4CH 2NMe2-?C,N)(DMPP)] (6), [Pd(C6H4CH2NMe2-?C,N) (solvent)]PF6 (7) and [Pd(C6H4CH2NMe2-?C,N) (DMPP)(solvent)]PF6 (8), have been compared with the help of multinuclear NMR spectroscopy. In general, the carboxylate group in the resulting seven-membered palladacycles is preferentially located next to the phenyl group of the benzylamine moiety, but this substitution pattern can be reversed by use of complexes containing electron-deficient and/or coordinatively-unsaturated palladium centres. A mechanism, based both on the experimental results described in this paper and on DFT computations, is proposed. © 2003 Elsevier Science B.V. All rights reserved.
KW - Alkyne insertion
KW - DFT calculation
KW - Dimethylbenzylamine
KW - NMR spectroscopy
KW - Palladacycles
KW - Regiochemistry
U2 - 10.1016/S0020-1693(03)00149-X
DO - 10.1016/S0020-1693(03)00149-X
M3 - Article
SN - 0020-1693
VL - 352
SP - 79
EP - 97
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
ER -