Highly regio- and stereoselective synthesis of multialkylated olefins through carbozirconation of alkynylboronates and sequential Negishi and Suzuki-Miyaura coupling reactions

Two Nobel couplings: The synthesis of tri- and tetraalkylated olefins has been achieved (see scheme). These multialkylated olefins were prepared by the zirconocene-mediated carbometalation of 1-alkynylboronates and subsequent sequential C-C bond formation with Negishi and Suzuki-Miyaura cross-coupling reactions using β-hydrogen-containing alkylzinc reagents and alkyl electrophiles as coupling partners.