Visible-Light-Mediated Cyclopropanation Reactions Of 3-Diazooxindoles With Arenes

The cyclopropanation reaction of 3-diazooxindoles with arenes was first accomplished using visible-light irradiation. A series of spiro[norcaradiene-7,3'-indolin]-2'-ones were synthesized for the first time in high yields and with excellent diastereoselectivities. The synthetic usefulness of this catalyst-free photochemical methodology is illustrated by the further controllable rearrangement and epoxidation reactions.