41073-19-2Relevant academic research and scientific papers
Regioselective Arene C?H Alkylation Enabled by Organic Photoredox Catalysis
Holmberg-Douglas, Natalie,Onuska, Nicholas P. R.,Nicewicz, David A.
, p. 7425 - 7429 (2020)
Expanding the toolbox of C?H functionalization reactions applicable to the late-stage modification of complex molecules is of interest in medicinal chemistry, wherein the preparation of structural variants of known pharmacophores is a key strategy for drug development. One manifold for the functionalization of aromatic molecules utilizes diazo compounds and a transition-metal catalyst to generate a metallocarbene species, which is capable of direct insertion into an aromatic C?H bond. However, these high-energy intermediates can often require directing groups or a large excess of substrate to achieve efficient and selective reactivity. Herein, we report that arene cation radicals generated by organic photoredox catalysis engage in formal C?H functionalization reactions with diazoacetate derivatives, furnishing sp2–sp3 coupled products with moderate-to-good regioselectivity. In contrast to previous methods utilizing metallocarbene intermediates, this transformation does not proceed via a carbene intermediate, nor does it require the presence of a transition-metal catalyst.
