A Chemoselective Reduction of Alkynes to (E)-Alkenes
Barry M. Trost,* Zachary T. Ball and Thomas Jöge
*Department of Chemistry, Stanford University, Stanford, California
94305-5080, Email: bmtrost
stanford.edu
B. M. Trost, Z. T. Ball, T. Joege, J. Am. Chem. Soc., 2002, 124, 7922-7923.
DOI: 10.1021/ja026457l
Abstract
The hydrosilylation of alkynes using the ruthenium catalyst [Cp*Ru(MeCN)3]PF6 gives only (Z)-trans addition products. Subsequent protodesilylation of the crude vinylsilane products by the action of cuprous iodide and TBAF provides a general trans-alkyne reduction, which is compatible with many sensitive functional groups.
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Details
This study presents a chemoselective method for the reduction of alkynes to (E)-alkenes using a two-step process involving hydrosilylation followed by protodesilylation. The authors, Barry M. Trost, Zachary T. Ball, and Thomas Jöge from Stanford University, developed a mild and efficient protocol using the complex [Cp*Ru(MeCN)3]PF6 to catalyze the hydrosilylation of alkynes with triethoxysilane, yielding vinylsilanes. Subsequent protodesilylation was achieved using cuprous iodide (CuI) and TBAF in THF, which facilitated the cleavage of the C-Si bond at lower temperatures, preserving sensitive functionalities. This method proved effective for a variety of alkynes, including those with conjugated esters, ketones, and propargyl alcohols, and allowed for the synthesis of trans-olefins with high chemoselectivity. The study highlights the dual role of CuI in moderating TBAF reactivity and facilitating desilylation, offering a general solution for the trans reduction of alkynes. The authors acknowledge the support from the National Science Foundation, the National Institutes of Health, and Stanford University. The findings provide a significant advancement in the selective synthesis of trans-olefins, with potential applications in complex molecule synthesis.
Key Words
ID: J48-Y2002-1190
