Synthesis of Weinreb Amides via Pd-Catalyzed Aminocarbonylation of Heterocyclic-Derived Triflates
作者:A. Deagostino、Paolo Larini、Ernesto G. Occhiato、Lorena Pizzuto、Cristina Prandi、Paolo Venturello
DOI:10.1021/jo7024898
日期:2008.3.1
lactone-, and thiolactone-derived triflates into N-methoxy-N-methyl or morpholine Weinreb amides has been realized using Pd-catalyzed aminocarbonylation under CO atmospheric pressure and at room temperature. The carbonylative coupling can be efficiently carried out with 2% of catalyst in the presence of Xantphos as a ligand. The amides smoothly react with nucleophiles to afford acylated aza-, oxa-, and
o-Benzenedisulfonimide has been used for the first time as a Brønsted acid catalyst to induce electrocyclization of dienones into cyclopentenones (Nazarov reaction). The catalyst has been used in various organic solvents or under solvent-free conditions and it is entirely recoverable from the reaction mixture. The versatility and the effectiveness of the proposed procedure is demonstrated on a wide range of both activated and inactivated substrates.