Aw. Fatland et Be. Eaton, Cobalt-catalyzed alkyne-nitrile cyclotrimerization to form pyridines in aqueous solution, ORG LETT, 2(20), 2000, pp. 3131-3133
[GRAPHICS]
A new, water-soluble cobalt(I) catalyst has been used in the aqueous, chemo
specific, cyclotrimerization of one nitrile with two alkynes for the synthe
sis of highly functionalized pyridines. Several different functional groups
are well incorporated in this transformation, including unprotected alcoho
ls, ketones, and amines. Double isotopic crossover data, as well as nitrile
dependence on the rate of product formation, suggest associative rate-dete
rmining coordination of the nitrile.