The continuum of carbon-hydrogen (C-H) activation mechanisms and terminology

The field of C-H activation has boomed in the past two decades, but the diverse and overlapping terms used in the literature can be difficult to parse. Here the authors review key mechanistic concepts and offer a guide to the perplexed. As a rapidly growing field across all areas of chemistry, C-H activation/functionalisation is being used to access a wide range of important molecular targets. Of particular interest is the development of a sustainable methodology for alkane functionalisation as a means for reducing hydrocarbon emissions. This Perspective aims to give an outline to the community with respect to commonly used terminology in C-H activation, as well as the mechanisms that are currently understood to operate for (cyclo)alkane activation/functionalisation.