Artículos de revistas
The mechanism of the stille reaction investigated by electrospray ionization mass spectrometry
Registro en:
Journal of Organic Chemistry 72 (15): 5809-5812
0022-3263
Autor
Santos, L.S.
Rosso, G.B.
Pilli, R.A.
Eberlin, M.N.
Institución
Resumen
Leonardo Silva Santos. Universidad de Talca, Instituto de Química de Recursos Naturales, P.O. Box 747, Talca, Chile. On-line monitoring of Stille reactions was performed via direct infusion electrospray ionization mass spectrometry (ESI-MS) and its tandem version (ESI-MS/MS). When operated in the positive ion mode, ESI(+)-MS was able to transfer, directly from solution to the gas phase, the species involved in all main steps of a Stille reaction, that is, the catalytically active palladium species Pd(PPh3)2, in its molecular ion form as well as the key cationic Pd(II) intermediates, including cyclic IPd-(CH2CH)Sn species. When searching for anionic species, ESI(-)-MS monitoring showed I- as the only anion detectable in the reaction medium. A detailed catalytic cycle for a Stille reaction was elaborated in which reaction intermediates and the previously elusive catalytically active Pd(0) species are shown in association with the respective ionic species intercepted by ESI-MS and further characterized by ESI-MS/MS.