Alkyne Semihydrogenation with a Well-Defined Nonclassical Co–H<sub>2</sub> Catalyst: A H<sub>2</sub> Spin on Isomerization and <i>E</i>-Selectivity
作者:Kenan Tokmic、Alison R. Fout
DOI:10.1021/jacs.6b08128
日期:2016.10.19
The reactivity of a co(I)-H-2 complex was extended toward the semihydrogenation of internal alkynes. Under ambient temperatures and moderate pressures of H-2, a broad scope of alkynes were semihydrogenated using a Co-I-N-2 precatalyst, resulting in the formation of trans-alkene products. Furthermore, mechanistic studies using H-1, H-2, and parahydrogen induced polarization (PHIP) transfer NMR spectroscopy revealed cis -hydrogenation of the alkyne occurs first. The Co-mediated alkene isomerization afforded the E-selective products from a broad group of alkynes with good yields and E/Z selectivity.
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