Catalytic Chemoselective and Stereoselective Semihydrogenation of Alkynes to E-Alkenes Using the Combination of Pd Catalyst and ZnI2

• DOI: 10.1021/acs.orglett.8b03295
• Publication Date: 2018-11-29T15:30:12Z
• Authors: Radhouan Maazaoui; Raoudha Abderrahim; Fabrice Chemla; Franck Ferreira; Alejandro Perez-Luna; Olivier Jackowski
• Keywords: [CHIM]Chemical Sciences; 01 natural sciences; 0104 chemical sciences

An efficient E-selective semihydrogenation of internal alkynes was developed under low dihydrogen pressure and low reaction temperature from commercially available reagents: Cl2Pd(PPh3)2, Zn0, and ZnI2. Kinetic studies and control experiments underline the significant role of ZnI2 in this process under H2 atmosphere, establishing that the transformation involves syn-hydrogenation followed by isomerization. This simple and easy-to-handle system provides a route to E-alkenes under mild conditions.