Synfacts 2013; 9(5): 0535
DOI: 10.1055/s-0033-1338330
Metal-Mediated Synthesis
© Georg Thieme Verlag Stuttgart · New York

Catalytic Semireduction of Alkynes to Alkenes

Contributor(s):
Paul Knochel
,
Andreas K. Steib
Whittaker AM, Lalic G * University of Washington, Seattle, USA
Monophasic Catalytic System for the Selective Semireduction of Alkynes.

Org. Lett. 2013;
15: 1112-1115
Further Information

Publication History

Publication Date:
17 April 2013 (online)

 

Significance

A novel copper-catalyzed semireduction of alkynes to alkenes has been disclosed. 0.5 to 2 mol% of a copper catalyst in combination with polymethylhydrosiloxane and isobutyl alcohol efficiently reduced terminal and internal alkynes, even in the presence of nitro and iodo groups.


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Comment

The authors propose the following mechanism: the silane transfers its hydride to the copper catalyst and a subsequent hydrocupration of the alkyne takes place. Protonation of this alkenyl-copper intermediate by the alcohol forms a copper alkoxide and the desired product.


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