Recent development in transition metal-catalysed C-H olefination.

Transition metal-catalysed functionalizations of inert C-H bonds to construct C-C bonds represent an ideal route in the synthesis of valuable organic molecules. Fine tuning of directing groups, catalysts and ligands has played a crucial role in selective C-H bond (sp or sp) activation. Recent developments in these areas have assured a high level of regioselectivity in C-H olefination reactions. In this review, we have summarized the recent progress in the oxidative olefination of sp and sp C-H bonds with special emphasis on distal, atroposelective, non-directed sp and directed sp C-H olefination. The scope, limitation, and mechanism of various transition metal-catalysed olefination reactions have been described briefly.