Ruthenium-Catalyzed Oxidative Amidation of Alkynes to Amides
Abstract: Complex CpRuCl(PPh3)(2) catalyzes reactions of terminal alkynes with 4-picoline N-oxide and primary and secondary amines to afford the corresponding amides. The reactions occur in chlorinated solvent and aqueous medium, showing applications in peptide chemistry. Stoichiometric studies reveal that the true catalysts of the processes are the vinylidene cations [CpRu(=C=CHR)(PPh3)(2)](+) which are oxidized to the Ru(eta(2)-CO)-ketenes by the N-oxide. Finally, nucleophilic additions of primary and secondary amines to the free ketenes yield the corresponding amides.
Author(s): Alvarez-Perez, A; Esteruelas, MA; Izquierdo, S; Varela, JA; Saa, C
ORGANIC LETTERS
Volume: 21 Pages: 5346-5350 Published: JUL 5 2019
PDF: Ruthenium-Catalyzed Oxidative Amidation of Alkynes to Amides
DOI: 10.1021/acs.orglett.9b01993
