Visible light-driven carbamoyloxylation of the α-C(sp 3 )-H bond of arylacetones via radical-initiated hydrogen atom transfer.

Photocatalytic synthesis has emerged as an efficient route to transform CO 2 into functionalized organic carbamates by photocatalysis. Herein, a catalyst-free carbamoyloxylation of arylacetones with CO 2 and amines under visible light was developed for the synthesis of O -β-oxoalkyl carbamates in yields up to 93%. This protocol proceeded smoothly with the assistance of inexpensive carbon tetrabromide at room temperature under atmospheric CO 2 pressure, leading to simultaneous construction of C-O and C-N bonds. Mechanism studies suggested the photoinduced hydrogen atom transfer (HAT) pathway followed by radical addition or single electron transfer (SET).