Scope of Ru(II)-catalyzed synthesis of pyridines from alkynes and nitriles

Jesús A Varela; Luis Castedo; Carlos Saá

doi:10.1021/jo035050b

Scope of Ru(II)-catalyzed synthesis of pyridines from alkynes and nitriles

J Org Chem. 2003 Oct 31;68(22):8595-8. doi: 10.1021/jo035050b.

Authors

Jesús A Varela¹, Luis Castedo, Carlos Saá

Affiliation

¹ Departamento de Química Orgánica y Unidad Asociada al CSIC, Facultad de Química, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.

PMID: 14575491
DOI: 10.1021/jo035050b

Abstract

Pyridines can be efficiently synthesized by Ru(II)-catalyzed [2 + 2 + 2] cycloaddition of 1,6-diynes to alpha,omega-dinitriles or electron-deficient nitriles or by Ru(II)-catalyzed [2 + 2 + 2] cocyclization of electron-deficient alkynes and electron-deficient nitriles. The reactions with dinitriles seem likely to proceed via ruthenacyclopentadiene intermediates and the reactions with electron-poor nitriles via azaruthenacyclopentadienes. The reaction with asymmetric electron-deficient alkynes affords 2,3,6-trisubstituted pyridines in good yield.