Intramolekulare Alkoxycyanierungen und Alkoxyacylierungen: Neue Alkendifunktionalisierungen für den Aufbau von Sauerstoffheterocyclen

Asymmetric Synthesis of Heterocyclic γ-Amino-Acid and Diamine Derivatives by Three-Component Radical Cascade Reactions

An enantioselective three-component radical reaction of quinolines or pyridines with enamides and α-bromo carbonyl compounds by dual photoredox and chiral Brønsted acid catalysis is presented. A range of valuable chiral γ-amino-acid derivatives are accessible in high chemo-, regio-, and enantioselectivity from simple, readily available starting materials under mild reaction conditions. Using the same strategy, the asymmetric synthesis of 1,2-diamine derivatives is also reported.

Alkene 1,2-Difunctionalization by Radical Alkenyl Migration

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.

PhSO2 SCF2 H: A Shelf-Stable, Easily Scalable Reagent for Radical Difluoromethylthiolation

A new shelf-stable and easily scalable difluoromethylthiolating reagent S-(difluoromethyl) benzenesulfonothioate (PhSO₂ SCF₂ H) was developed. PhSO₂ SCF₂ H is a powerful reagent for radical difluoromethylthiolation of aryl and alkyl boronic acids, decarboxylative difluoromethylthiolation of aliphatic acids, and a phenylsulfonyl-difluoromethylthio difunctionalization of alkenes under mild reaction conditions.

Highly enantioselective dearomatizing formal [3+3] cycloaddition reactions of N-acyliminopyridinium ylides with electrophilic enol carbene intermediates

A effective dearomatizing formal [3+3]-cycloaddition reaction triggered by Rh(II)-catalyzed dinitrogen extrusion of enoldiazoacetates followed by vinylogous addition of metal enolcarbenes to N -acyliminopyridinium ylides that produces highly substituted 1,2,3,6-tetrahydropyridazines in up to 98% ee and in high yield has been developed.

Enantioselective functionalization of radical intermediates in redox catalysis: copper-catalyzed asymmetric oxytrifluoromethylation of alkenes

A method for the efficient enantioselective oxytrifluoromethylation of alkenes has been developed using a copper catalyst system. Mechanistic studies are consistent with a metal-catalyzed redox radical addition mechanism, in which a C–O bond is formed via the copper-mediated enantioselective trapping of a prochiral alkyl radical intermediate derived from the initial trifluoromethyl radical addition.