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Titolo:
Kinetic evidence for pi-complex formation prior to oxidative addition of propargyl halides to triphenylphosphine - Platinum(0) complexes
Autore:
Nishida, T; Ogoshi, S; Tsutsumi, K; Fukunishi, Y; Kurosawa, H;
Indirizzi:
Osaka Univ, Fac Engn, Dept Appl Chem, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 pl Chem, Suita, Osaka 5650871, Japan
Titolo Testata:
ORGANOMETALLICS
fascicolo: 22, volume: 19, anno: 2000,
pagine: 4488 - 4491
SICI:
0276-7333(20001030)19:22<4488:KEFPFP>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
ALLENYL COMPLEXES; ISOMERIZATION; PALLADIUM; MECHANISM; ARYL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
18
Recensione:
Indirizzi per estratti:
Indirizzo: Nishida, T Osaka Univ, Fac Engn, Dept Appl Chem, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 ita, Osaka 5650871, Japan
Citazione:
T. Nishida et al., "Kinetic evidence for pi-complex formation prior to oxidative addition of propargyl halides to triphenylphosphine - Platinum(0) complexes", ORGANOMETAL, 19(22), 2000, pp. 4488-4491

Abstract

The mechanism of oxidative addition of phenylpropargyl halides to Pt(PPh3)(4) to give Pt(eta (1)-CH2C=CPh)(X)(PPh3)(2) has been investigated on the basis of the kinetics of the reaction and stereomeric analysis of the products. The kinetic results of the reaction showed the contributions of two pathways involving Pt(PPh3)(3) and Pt(PPh3)(3) complexes as active species. The second-order rate constants for both pathways were on the order of 10(3) larger than the corresponding rate constants of the oxidative addition reaction of CH3I, Moreover, both active species and the substrate halide gave, as the kinetic product, the isomer having two PPh3 groups located cis, which is also in sharp contrast to the case of the reaction of CH3I. It is proposed that the rate-determining step in the reaction involving Pt(PPh3)(2) is the coordination of the C=C bond to Pt(PPh3)(2) to form Pt(eta (2)-PhC=CCH2X)(PPh3)(2), which subsequently undergoes rapid collapse to the eta (3)-propargyl complex [Pt(eta (3)-CH2CCPh)(PPh3)(2)]X and eventually to cis-Pt(eta (1)-CH2C=CPh)(X)(PPh3)(2). The reaction of Pt(PPh3)(3) may also involve a rate-determining C=C bond coordination step.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/09/20 alle ore 08:23:51