Metal-free borylative ring-opening of vinyl epoxides and aziridines.
A rational approach towards the borylative ring-opening of vinylepoxides and vinylaziridines, by the in situ formed MeO(-)→bis(pinacolato)diboron adduct, has been developed. The enhanced nucleophilic character of the Bpin (sp(2)) moiety from the reagent favours the SN2' conjugated B addition with the concomitant opening of the epoxide and aziridine rings. The reaction proceeds with total chemoselectivity towards the polyfunctionalised (-OH or -NHTs) allyl boronate. Theoretical calculations have determined the transition states that come from the reaction of the vinylic substrates with the activated MeO(-)→bis(pinacolato)diboron adduct, and a plausible mechanism for the organocatalytic borylative ring opening reaction has been suggested.
Department de Química Física i Inorgànica, Univ. Rovira i Virgili, C/Marcel.lí Domingo s/n, 43007 Tarragona, Spain. mariaelena.fernandez@urv.cat.
Xavier
X
Sanz
Graham M
GM
Lee
Cristina
C
Pubill-Ulldemolins
Amadeu
A
Bonet
Henrik
H
Gulyás
Stephen A
SA
Westcott
Carles
C
Bo
Elena
E
Fernández