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Palladium-Catalyzed Complete Regio- and Stereoselective Vicinal trans-Bisphosphination of Terminal Alkynes with Air-
1Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-4-37 Takeda, Kofu, Yamanashi 400-8510, Japan.
Abstract:
A palladium-catalyzed completely regio- and stereoselective vicinal trans-bisphosphination of terminal alkynes has been achieved using air- and moisture-stable tetraphenyldiphosphine disulfide as the phosphorus source. The developed system shows outstanding catalytic activity (cat: min 0.5 mol %) with excellent atom-economy (E-factor = 1.18), producing the corresponding vic-bisphosphinoalkenes in up to 100% yields as the complete E-isomers. Control experiments clearly demonstrate the important role of the palladium catalyst in two distinct and concerted catalytic cycles. This system can be used for gram-scale synthesis, catalyst recycling, and further molecular transformations.
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