Metal‐Free Promoted CF₂/CF₃‐Difunctionalization of Unactivated Alkenes

Abstract

An operationally simple radical difluoroalkylation/trifluoromethylation and alkynylation of unactivated alkenes under mild conditions has been developed. Through this protocol, a series of CF2/CF3‐ substituted linear alkynyl ketones were synthesized via a unique 1,2‐alkynyl radical migration. Notably, no transition‐ metal catalyst is needed in the developed reaction system, and excellent functional group compatibility was observed.magnified image

1,2-Alkynyl Functionalization of Unactivated Alkenes via Diverse Radical-Triggered Functional Group Migration

“…The intermolecular kinetic isotope effect experiment demonstrated that the cleavage of Csp 3 –H of dichloromethane was the product-determining step of this procedure (Scheme c) . Thus, based on the above results and previous reports, we proposed a plausible mechanism for this process, which was depicted in Scheme . Initially, the targeted R radicals were generated with the corresponding conditions.…”

Promising reagents for difluoroalkylation

“…Another organic base-promoted difluoroalkylation reaction of 1,4-enynes with ICF 2 CO 2 Et was realized by yje Liang group. 76 Various functional groups were compatible with this reaction. A possible mechanism is outlined in Scheme 20.…”

Fluoroalkyl Iodides in Fluoroalkylative Difunctionalization of C−C Multiple Bonds

“…Addition of the fluoroalkyl radical to 1,n-enynes derived from tertiary propargyl alcohols delivers acyclic products with the migration of alkynyl moiety (Scheme 33). Two methodologies for the reaction of 1,6-or 1,7-enynes with simple iodoperfluoroalkanes, [132] and 1,3-enynes with ethyl iododifluoroacetate [133] have been developed, both utilizing the formation of an EDA complex of iodofluoroalkane and amine for the formation of the fluoroalkyl radical. Migration of the alkynyl fragment is achieved via a radical sequence of cyclization and fragmentation.…”