Catalytic Carbon–Boron Bond Formation via Activation of Alkane C–H Bonds

Abstract

Alkanes are extremely unreactive toward nucleophiles and electrophiles because they are composed of nonpolar, strong, saturated C–H and C–C bonds. Thus, although they are abundant natural resources, alkanes are notoriously underutilized in chemical synthesis, and the selective functionalization of alkane to produce useful organic products is a major challenge in organic chemistry. Among different C–H functionalization methods of alkanes, transition metal-catalyzed functionalization has the selectivity advantage (tertiary C–H < secondary C–H < primary C–H bonds) and can afford more desirable terminally functionalized alkanes. Direct functionalization of the C–H bonds of alkanes to C–B bonds is a particularly attractive method because the boron moiety of alkane can be converted to a variety of functional groups using the rich chemistry of organoboron compounds. This chapter describes the development of direct borylation of alkane C–H bonds catalyzed by transitional metal complexes since 1995. The scope of the reaction, mechanistic understanding via computational studies and kinetic experiments, and challenges for broader applications in practical organic synthesis are discussed.