Domino Heck/borylation sequence towards indolinone-3-methyl boronic esters: trapping of the σ-alkylpalladium intermediate with boron

Abstract

Pd-catalyzed domino Heck/borylation of acrylamides with B₂pin₂ is reported to generate synthetically useful indolinone-3-methyl boronic esters, via capturing σ-alkyl palladium with boron. Further functionalization of the obtained boronic ester qualify it as a new starting point for the functionalization of specific C(sp³)–H bond. Moreover, the application of an Ugi-adduct as starting material or B₂nep₂ as an alternative boron source works equally well, making this a broadly applicable and robust method for the formation of a C–C and C–B bond in a single operation.