Photochemical Alkene Trifluoromethylimination Enabled by Trifluoromethylsulfonylamide as a Bifunctional Reagent

Abstract

Herein, we disclose a facile and versatile trifluoromethylimination of alkene with a rationally designed N-(diphenylmethylene)-1,1,1-trifluoromethanesulfonamide as a bench-stable and readily accessible carboamination reagent. Enabled by an energy transfer (EnT) process, an array of alkenes were able to be facilely CF3-iminated under metal-free photocatalytic conditions. The mild reaction conditions and good functional group compatibility render this protocol highly valuable for the difunctionalization of olefins with structural complexity and diversity.

Recent Advances in Visible Light‐Mediated Radical Fluoro‐alkylation, ‐alkoxylation, ‐alkylthiolation, ‐alkylselenolation, and ‐alkylamination

“…Recently, Xiang, Yang, and coworkers presented the trifluoromethylimination of alkenes utilizing trifluoromethylsulfonylamide ( 30 ) as a bifunctional reagent (Scheme 26). [107] Proposing an energy transfer process, 30 is thought to undergo homolysis to generate ⋅CF 3 and iminyl radical. ⋅CF 3 adds to the olefin to generate the radical adduct that can couple with the generated iminyl radical.…”

Three-Component Photochemical 1,2,5-Trifunctionalizations of Alkenes toward Densely Functionalized Lynchpins

“…Furthermore, radical attack to vinyl azides, followed by dinitrogen extrusion and 1,5-HAT of the formed iminyl radical to generate the remote radical was used to 1,5-difunctionalize alkenes . In several methods, the desired 5-position radical is formed via remote CN abstraction after initial radical attack to the alkene, enabling a 1,2,5-trifunctionalization reaction. , Another particularly elegant alkene 1,2,5-trifunctionalization was reported by Han, featuring the migration of an in situ phosphorylated alcohol as the key reaction step …”

“…1,5-Functional group distances are frequently found in organic molecules and prominently present in precursors for the preparation of six-membered heterocyclic systems . Since the simultaneous introduction of both functional groups into simple building blocks constitutes an ideal strategy to access these valuable structures, radical 1,5-difunctionalizations of alkenes have recently attracted increased attention (Figure A). ,− An established approach toward this goal is the addition of a radical to vinylcyclopropanes, followed by opening of the three-membered cycle . Another 1,5-difunctionalization reaction of alkenes via ring opening was developed by Feng, relying on radical attack to 4-isoxazolines with subsequent N–O bond cleavage and radical relocation to the remote position .…”

Chemo-divergent Cyano Group Migration: Involving Elimination and Substitution of the Key α-Thianthrenium Cyano Species

“…The highly reductive reactivity of intermediate C 1 , derived from cyano group migration of cyanohydrins, is readily oxidized into the corresponding ketones (Scheme B) . Intermediate C 2 , obtained from the cyano group migration of 1,1-dinitrile and benzonitrile, underwent further functionalization through radical coupling or nucleophilic attack after oxidation. , However, controlling the diastereoselectivity of products was proven to be challenging as a result of the low energy barrier differences between transition states. , Thus, the development of novel and selective methodology to capture and transfer intermediate C 2 is highly desirable.…”