Photoinduced Pd-Catalyzed C_sp2–H/C_sp3–H Dehydrocoupling Reaction Employing Polyhaloaromatics as the Dehydrogenating Agent

Abstract

A mild strategy for intermolecular cross-dehydrocoupling of Csp2–H bonds and Csp3–H bonds has been developed with the aid of photoinduced Pd catalysis. Polyhalogenated arenes can be used as the efficient dehydrogenating agent, which enables multifold transfer of carbon radical to avoid the production of stoichiometric or excess wasted arenes. In this strategy, substituted styrenes and N-arylacrylamides with simple ethers or amides as the coupling partners gives the corresponding internal alkenes and benzolactams with moderate to good yield.

Recent Advances in Visible Light Induced Palladium Catalysis

“…In 2022, the Yin group employed hexabromobenzene (HBB) for the C(sp 3 )−H alkenylation of activated substrates (Scheme 13). [47] Only 0.3 equivalents of HBB were required, indicating that each HBB molecule can undergo multiple HAT events. As with most reactions involving aryl radical‐mediated intermolecular HAT, [48] the activated substrate was used as a solvent to ensure good yields.…”