Controlling the reactive species during the synthesis of complex aliphatic chains containing a quaternary carbon is incredibly difficult. In this paper, we efficiently controlled both radical and cationic species in the presence of a copper catalyst. This radical-polar crossover reaction system enables the three-component coupling of styrenes, alcohols, and α-bromocarbonyl compounds as a tertiary alkyl source at room temperature. Mechanistic studies indicated that the reaction contains both radical and cationic species.

A light-driven atom-transfer radical substitution (ATRS) and carboesterification reaction of alkenes with alkyl halides has been developed using PTH as the organo-photoredox catalyst. Two types of products were obtained, depending on the additive and solvent used during the reaction. Primary, secondary, and tertiary alkyl halides reacted to give the ATRS products. This protocol has several advantages: it requires mild reaction conditions and a low catalyst loading and exhibits a broad substrate scope and good functional group tolerance. Mechanistic studies indicate that alkyl radicals might be generated as the key intermediates via photocatalysis, providing a new direction for ATRS reactions.

The transition-metal-free synthesis of sterically congested ethers and heterocycles via the stereospecific etherification and hydroamidation of α-bromocarboxamides and alkynols.