H<sub>2</sub>O as the Hydrogen Donor: Stereo-Selective Synthesis of <i>E</i>- and <i>Z</i>-Alkenes by Palladium-Catalyzed Semihydrogenation of Alkynes
Jianwu Shi, Taowen Ye, Jin Dong, Aifen Liu, Tong Xu, Mingliang Tai, Lei Zhang, Chengniu Wang
Abstract
High Resolution Image Download MS PowerPoint Slide It is very desirable to develop a facile controllable method for selective semihydrogenation of alkynes to alkenes with a cheap and safe hydrogen donor but remains a big challenge. H 2 O is one of the best choices of the transfer hydrogenation agent of the world, and the development of methods for synthesizing E - and Z -alkenes using H 2 O as the hydrogen source is worthwhile. In this article, a palladium-catalyzed synthesis of E - and Z -alkenes from alkynes using H 2 O as the hydrogenation agent was reported. The use of di- tert -butylphosphinous chloride ( t -Bu 2 PCl) and triethanolamine/sodium acetate (TEOA/NaOAc) was essential for the stereo-selective semihydrogenation of alkynes. The general applicability of this procedure was highlighted by the synthesis of more than 48 alkenes, with good yields and high stereoselectivities.