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Published on: April 22, 2016
Visible-Light-Induced Semihydrogenation of Alkynes
Changhao Feng1, Jinbo Wang1, Liyuan Wang1
1Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, P.R. China.
Abstract:
The semihydrogenation of alkynes is an important and direct synthetic strategy to obtain Z-alkenes. Although great success has been achieved with various transition metal catalysts, a mild and metal-free approach is still highly desired. Herein, we report a metal-free photocatalytic transfer hydrogenation method for the semireduction of alkynes, wherein γ-terpinene acts as the reductant, while both H2O and γ-terpinene serve as hydrogen sources. A range of alkynes can be efficiently converted to Z-alkenes via transfer hydrogenation followed by photoinduced E → Z isomerization. This green and sustainable approach provides a practical alternative to the synthesis of combretastatin A-4.
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