Artículos de revistas
Revisiting The Intermolecular Fujiwara Hydroarylation Of Alkynes
Registro en:
European Journal Of Organic Chemistry. Wiley-v C H Verlag Gmbh, p. 1794 - 1803, 2017.
1434-193X
1099-0690
WOS:000398575300018
10.1002/ejoc.201700033
Autor
Godoi
Marla N.; de Azambuja
Francisco; Martinez
Pablo David G.; Morgon
Nelson H.; Santos
Vanessa G.; Regiani
Thais; Lesage
Denis; Dossmann
Heloise; Cole
Richard B.; Eberlin
Marcos N.; Correia
Carlos Roque D.
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The Fujiwara hydroarylation of alkynes was reinvestigated using the addition of indole to methyl or ethyl phenyl-propiolate catalyzed by Pd(OAc)(2) as a model reaction. Reactions were monitored by both H-1 NMR spectroscopy and electrospray ionization mass spectrometry (ESI/MS), and also through reactions carried out in the gas phase using MS/MS experiments. Contrary to the original suggestion for exclusive heteroarene activation, the data supports the coexistence of both heteroarene activation (C-H activation) and alkyne activation (Friedel-Crafts- type pathway). Under the reaction conditions used in this work, intermediates for both mechanisms were detected by NMR spectroscopy and MS, but alkyne activation seems to be predominant according to H-1 NMR spectroscopic studies and theoretical predictions. Alkyne activation is promoted by the coordination of an electrophilic palladium species to the C-C triple bond, followed by nucleophilic attack of the heteroaryl counterpart. Two previously undetected equilibria in this reaction involving the vinylpalladium intermediates and the final products were also found to be critical to the stereoselectivity of the reaction. 13 1794 1803 Sao Paulo Research Foundation (FAPESP) [2011/23832-6, 2010/11068-7, 2008/00122-0, 2010/00257-3] Brazilian National Research Council (CNPq) [457027/2014-2] Universite Pierre et Marie Curie Institut Parisien de Chimie Moleculaire Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)