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Published on: February 7, 2017
Regioselective Formation of (E)-β-Vinylstannanes with a Topologically Controlled Molybdenum-Based Alkyne
Kyle A Mandla1, Curtis E Moore1, Arnold L Rheingold1
1Department of Chemistry and Biochemistry, Section of Synthesis, Materials and Chemical Biology, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, CA, 92093, USA.
Abstract:
The regioselective formation of (E)-β-vinylstannanes has been a long-standing challenge in transition-metal-catalyzed alkyne hydrostannation. Herein, we report a well-defined molybdenum-based system featuring two encumbering m-terphenyl isocyanides that reliably and efficiently delivers (E)-β-vinylstannanes from a range of terminal and internal alkynes with high regioselectivity. The system is particularly effective for aryl alkynes and can discriminate between alkyl chains of low steric hindrance in unsymmetrically substituted dialkyl alkynes. Catalytic hydrostannation with this system is also characterized by an electronic effect that leads to a decrease in regioselectivity when electron-withdrawing groups are present on the alkyne substrate.
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