Catalytic alkane C–H functionalization by carbene insertion into unactivated C(sp3)–H bonds

The direct and selective C–H functionalization of unactivated alkanes has been an outstanding yet challenging goal of modern synthetic chemistry. The C(sp³)–H insertion of metal carbenes has established itself as one of the most powerful methodologies for achieving alkane C–H functionalization, allowing for exquisite regioselectivity and stereoselectivity without resorting to the usage of directing groups. This review highlights the early and recent developments in the C–H functionalization of simple alkanes by carbene insertion into unactivated C(sp³)–H bonds. This review is organized into four sections: metal-catalyzed insertion of acceptor, acceptor/acceptor, donor/acceptor and donor carbenes into the C–H bonds of cycloalkanes and linear alkanes, respectively.