Cooperative NHC/Photoredox Catalyzed Ring‐Opening of Aryl Cyclopropanes to 1‐Aroyloxylated‐3‐Acylated Alkanes
作者:Zhijun Zuo、Constantin G. Daniliuc、Armido Studer
DOI:10.1002/anie.202110304
日期:2021.11.22
Ring-opening/arylcarboxylation/acylation of mono, di and trisubstituted cyclopropanes enabled by cooperative NHC and organophotoredox catalysis for the preparation of γ-aroyloxy ketones is reported. Key step is the radical/radical cross- coupling of a benzylic radical generated in the photoredox catalysis cycle and a ketyl radical formed in the NHC catalysis cycle.
A copper-catalyzed 1,3-aminothiocyanation of arylcyclopropanes with N-fluorobenzenesulfonimide (NFSI) and trimethylsilyl isothiocyanate (TMSNCS) has been developed for the first time, efficiently synthesizing a series of γ-aminothiocyanate derivatives in moderate to excellent yields from readily available substrates under mild conditions. The practicability of the reaction was demonstrated by gram-scale
Imidazotetrazines as Weighable Diazomethane Surrogates for Esterifications and Cyclopropanations
作者:Riley L. Svec、Paul J. Hergenrother
DOI:10.1002/anie.201911896
日期:2020.1.27
Diazomethane is one of the most versatile reagents in organic synthesis, but its utility is limited by its hazardous nature. Although alternative methods exist to perform the unique chemistry of diazomethane, these suffer from diminished reactivity and/or correspondingly harsher conditions. Herein, we describe the repurposing of imidazotetrazines (such as temozolomide, TMZ, the standard of care for
In this paper, we reported a copper-catalyzed ring-openingreaction of arylcyclopropanes by N-fluorobenzenesulfonimide, leading to N-allylsulfonamides in moderate to good yields. This procedure tolerated bromo, fluoro, trifluoromethyl, phenyl and alkyl groups in the phenyl, proceeding with a sequential ring-opening of arylcyclopropanes, and copper-mediated β-H elimination of alkyl radical.
A facile approach for the synthesis of enantiopure γ-amino nitriles by copper-catalyzed aminocyanation of arylcyclopropanes is disclosed, which undergoes the highly enantioselective ring-opening reaction of cyclopropanes. The strategy utilizes N-fluorobenzenesulfonimide as nucleophilic nitrogen source as well as oxidant and trimethylsilyl cyanide as the other nucleophile, and it probably operates via