Metal-free photo-induced heteroarylations of C-H and C-C bonds of alcohols by flow chemistry

Practical, metal-free heteroarylations of C-H and C-C bonds of unprotected aliphatic alcohols are accomplished in a 'stop-flow' micro-tubing reactor. The reactions proceed through alkoxy radical-triggered hydrogen atom transfer and beta-C(sp(3))-C(sp(3)) bond rupture under mild photochemical conditions, leading to a plethora of valuable functionalized heteroarenes. The reaction is amenable for late-stage functionalization of complex heteroarenes, and can be readily scaled up by a continuous-flow method. The protocol features many advantages including good regioselectivity, broad functional group compatibility, and easy operation, and may find potential use in medicinal chemistry.

Automated summary

Practical, metal-free heteroarylations of C-H and C-C bonds of unprotected aliphatic alcohols were successfully achieved using a 'stop-flow' micro-tubing reactor. This reaction proceeds through alkoxy radical-triggered hydrogen atom transfer and beta-C(sp(3))-C(sp(3)) bond rupture under mild photochemical conditions, resulting in the production of valuable functionalized heteroarenes. The protocol offers numerous advantages, including good regioselectivity, broad functional group compatibility, and easy operation, and shows potential for use in medicinal chemistry.