Hydroalumination of silylacetylenes: a novel and highly stereoselective synthesis of (E)-telluro(silyl)ketene acetals and their applications in Sonogashira cross-coupling reactions

• Published in: Tetrahedron letters 2011-11, Vol.52 (46), p.6067-6071
• Main Authors: Kawasoko, Cristiane Y., Nazario, Carlos E.D., Santana, Amanda S., Viana, Luiz H., Hurtado, Gabriela R., Marques, Francisco A., Frensch, Gustavo, de Oliveira, Paulo R., Guerrero, Palimécio G., Carvalho, Diego B., Baroni, Adriano C.M.
• Format: Article
• Language: English
• Subjects: (Z)-1,4-Diorganyl-2-tri(organyl)silyl-1-buten-3-ynes; (Z)-β-Vinylorganosilane alanates; Acetals; Chemical reactions; Chemistry; Cross coupling; Exact sciences and technology; Hydroalumination; Organic chemistry; Organometalloidal and organometallic compounds; Palladium; Preparations and properties; Si derivatives; Sonogashira cross-coupling; Stereochemistry; Synthesis (chemistry); Telluro(silyl)ketene acetals; Tetrahedrons
• ISSN: 0040-4039; 1873-3581
• DOI: 10.1016/j.tetlet.2011.08.147

The hydroalumination of silylacetylenes with DIBAL-H followed by the addition of n-butyllithium generated in situ the (Z)-β-vinylorganosilane alanates intermediates, which were trapped with butyltellurenyl bromide (C4H9TeBr), furnishing exclusively the (E)-1-butyltelluro-1-tri(organyl)silyl-2-organyl-1-alkenes in 45–70% yields. These telluro(silyl)ketene acetals were utilized as substrates in Sonogashira cross-coupling Pd-catalyzed reactions, furnishing the (Z)-1,4-diorganyl-2-tri(organyl)silyl-1-buten-3-ynes with total control of regio- and stereochemistry in 62–80% yield.