title: Tandem gold self-relay catalysis for the synthesis of 2,3-dihydropyridin-4(1 H)-ones: combination of σ and π Lewis acid properties of gold salts.
abstract: The dual ability of gold salts to act as π- and σ Lewis acids has been exploited in a tandem self-relay catalysis. Thus, triphenylphosphanegold(I) triflate mediated the intramolecular carbonyl addition of the amide functionality of homoprogargyl amides to a triple bond. The formation of a σ complex of the gold salt with the intermediate oxazine promoted a nucleophilic addition followed by a Petasis-Ferrier rearrangement. This tandem protocol, catalyzed by the same gold salt under the same reaction conditions, gave rise to the efficient synthesis of 2,3-dihydropyridin-4-(1 H)-ones, which contain a cyclic quaternary α-amino acid unit. The asymmetric version was performed by generating the starting materials from the corresponding sulfinylimines.
authors.affiliation: Departamento de Química Orgánica, Universidad de Valencia, 46100-Burjassot (Spain); Laboratorio de Moléculas Orgánicas, Centro de Investigación Principe Felipe, 46012-Valencia (Spain). santos.fustero@uv.es.
authors.forename: Santos
authors.initials: S
authors.lastname: Fustero
authors.forename: Javier
authors.initials: J
authors.lastname: Miró
authors.forename: María
authors.initials: M
authors.lastname: Sánchez-Roselló
authors.forename: Carlos
authors.initials: C
authors.lastname: del Pozo
keywords: Lewis acids; alkaloids; autocatalysis; gold; transition-metal catalysis