A unified approach to access β-branched organoboron through coupling of boron-stabilized organozinc with alkyl halides

Abstract

A general and efficient strategy for the preparation of β-branched organoboron compounds through Ni-catalyzed coupling of BpinCH2ZnI with alkyl halides had been developed. In comparison with known methods such as Matteson homologation and the functionalization of 1,1-bisborylmethane, this reaction is more step-economical and has broader functional-group compatibility. Primary, secondary and the challenging tertiary alkyl halides are appropriate substrates to accomplish this transformation. The synthetic practicability of the prepared β-quaternary organoboronates was demonstrated by their conversion to other useful compounds.

Nickel-Catalyzed Negishi Cross-Coupling of Alkyl Halides, Including Unactivated Tertiary Halides, with a Boron-Stabilized Organozinc Reagent

“…Negishi cross-coupling represents one of the most fundamental methods for constructing carbon skeletons. , Since the pioneering work on nickel-catalyzed Negishi cross-coupling of dialkylzinc reagents with primary alkyl halides developed by the Knochel group, extensive efforts have been made to expand this field to include asymmetric variants . Nickel-catalyzed Negishi cross-coupling has become an indispensable tool for the construction of alkyl–alkyl bonds …”