Alkene-Directed, Nickel-Catalyzed Alkyne Coupling Reactions

• Published in: Journal of the American Chemical Society Vol. 126; no. 13; pp. 4130 - 4131
• Main Authors: Miller, Karen M, Luanphaisarnnont, Torsak, Molinaro, Carmela, Jamison, Timothy F
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 07.04.2004; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Exact sciences and technology; Organic chemistry; Physical Sciences; Science & Technology; TERMINAL EPOXIDES; HYDROGENATION; CYCLIZATIONS; 1,3-DIENES; KINETIC RESOLUTION; HYDROSILYLATION; COMPLEXES; STEREOCHEMISTRY; ALDEHYDES; HYDROFORMYLATION; Catalytic reaction; Nickel Complexes; Regioselectivity; Catalyst selectivity; Epoxide; Transition metal Complexes; Aldehyde; Complex catalyst; Experimental study; Catalyst activity; Alkyne; Chemical coupling
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0491735

In alkene-directed, nickel-catalyzed coupling reactions of 1,3-enynes with aldehydes and epoxides, the conjugated alkene dramatically enhances reactivity and uniformly directs regioselectivity, independent of the nature of the other alkyne substituent (aryl, alkyl (1°, 2°, 3°)) or the degree of alkene substitution (mono-, di-, tri-, and tetrasubstituted). These observations are best explained by a temporary interaction between the alkene and the transition metal center during the regioselectivity-determining step. The highly substituted 1,3-diene products are useful in organic synthesis and, in conjunction with a Rh-catalyzed, site-selective hydrogenation, afford allylic and homoallylic alcohols that previously could not be prepared in high regioselectivity (or at all) with related Ni-catalyzed alkyne coupling reactions.