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Stereodivergent Silylzincation of α-Heteroatom-Substituted Alkynes
Carolin Fopp1, Elise Romain2, Kevin Isaac2
1Institut für Chemie, Technische Universität Berlin , Strasse des 17. Juni 115, D-10623 Berlin, Germany.
Abstract:
Zinc reagents (Me2PhSi)2Zn and [(Me3Si)3Si]2Zn undergo highly regio- and stereoselective addition across the carbon-carbon triple bond of nitrogen-, sulfur-, oxygen-, and phosphorus-substituted terminal alkynes in the absence of copper or any other catalyst. Both reagents yield exclusively β-isomers, and the stereoselectivity is determined by the silyl group: Me2PhSi for cis or (Me3Si)3Si for trans. These stereodivergent silylzincation protocols offer an efficient access to heteroatom-substituted vinylsilanes with either double bond geometry, including trisubstituted vinylsilanes by one-pot electrophilic substitution of the intermediate C(sp(2))-Zn bond by copper(I)-mediated carbon-carbon bond formation.
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