Alkene 1,2‐Difunctionalization by Radical Alkenyl Migration

Abstract

Transition‐metal‐free radical α‐perfluoroalkylation with the accompanying vicinal β‐alkenylation of unactivated alkenes is presented. These radical cascades proceed by means of 1,4‐ or 1,5‐alkenyl migration by electron catalysis on readily accessed allylic alcohols. The reactions comprise a regioselective perfluoroalkyl radical addition with subsequent alkenyl migration and concomitant deprotonation to generate a ketyl radical anion that sustains the chain as a single‐electron‐transfer reducing reagent.

Electrochemical Alkynyl/Alkenyl Migration for the Radical Difunctionalization of Alkenes

“…Based on the above experimentalr esults and previous reports, [9,10,15] ap lausible mechanism for this electrochemical radical migration reaction was proposed in Scheme 8. First Scheme6.Follow-upc hemistry.…”

“…[9] The Studer group has developed ad ifunctionalization of alkynyl-substitutedt ertiary alcohol via 1,4-alkenyl migration. [10] These radical migration reactions mainly focused on the light initiation and metal catalysis, which usually need transition metal, photocatalysto radditives.…”

Electron Donor‐Acceptor Complexes in Perfluoroalkylation Reactions

“…Studer and colleagues have accomplished the α‐perfluoroalkyl‐β‐olefination[23a] and the α‐perfluoroalkyl‐β‐alkynylation[23b] of alkenes, according to Scheme .…”

“…Transition metal‐free radical α‐perfluoroalkylation with concomitant β‐alkynylation[23b] or β‐olefination[23a] of inactivated alkenes is shown to proceed by cascades reactions through electron‐catalysis and comprises a radical 1,4‐ or 1,5‐alkynyl[23b] (or alkenyl[23a]) migration from tertiary propargylic[23b] (or allylic[23a]) alcoholates to secondary or tertiary C‐radicals as the key step. In the case of alkynyl migration,[23b] it leads to a ketyl radical anion that sustains the chain as a SET reducing reagent. The electron catalysis is represented in Scheme .…”

Copper‐Catalyzed Heteroarylsilylation of Unactivated Olefins through Distal Heteroaryl Migration

“…Av ariety of solvents, which do not generally functiona sh ydrogen donor in radicalr eaction, was examined to assess the solvente ffect. Amongt hem, benzene was theb est one to deliver ag ood yield (entries [12][13][14][15][16][17]. Ac ontrol experiment withoutc oppers alt also led to the desired product 2a in modest yield, indicating that the copperc atalyst was not indispensable to the reaction but it indeedi mproved the reaction outcome (entry 18).…”