Visible‐Light Photoredox Alkylation of Heteroaromatic Bases Using Ethyl Acetate as Alkylating Agent

An efficient room‐temperature visible‐light photoredox α‐acyloxyalkylation reaction of N‐heteroarenes is reported, which relies on the use of ethyl acetate as a cheap and non‐conventional radical source. The direct C(sp2)‐C(sp3) coupling was extended to a diverse set of mono‐, bi‐, and tricyclic of N‐heteroaromatics, and the optimized photoredox protocol was successfully performed on a multigram scale. The scope of the alkylating agent was also explored and a plausible mechanism was proposed, involving photoinduced single‐electron transfer and hydrogen‐atom transfer processes. The direct Csp2‐Csp3 visible‐light photoredox cross‐dehydrogenative coupling of N‐heteroaromatics with ethyl acetate via the generation of 1‐acetoxyethan‐1‐yl radical is reported. This approach also uncovers ethyl acetate as a cheap and non‐conventional radical source in photoredox related organic synthesis.