Rearrangement Reaction Based on the Structure of N-Fluoro-N-alkyl Benzenesulfonamide

Abstract

A novel rearrangement reaction based on the structure of N-fluoro-N-alkyl benzenesulfonamide was developed. The reaction proceeded readily at 50 °C in formic acid and generated a variety of benzenesulfonamides and aldehydes or ketones simultaneously. The reaction mechanism is believed to be a concerted mechanism that consist of 1,2-aryl migration with the departure of fluorine anion via an SN2 mechanism. This rearrangement reaction features an interesting reaction mechanism, mild reaction conditions, simple operations, and a broad substrate scope.

N-Fluorobenzenesulfonimide (NFSI) analogs with deprotectable substituents: synthesis of β-fluoroamines via catalytic aminofluorination of styrenes

“…Compound 3 is a useful precursor that enables the easy introduction of various substituents on its nitrogen atom, for example, condensation of 3 with benzenesulfonyl chloride or benzoyl chloride in the presence of 2,6-lutidine gave the corresponding N–F reagents 1d – e (Scheme 2c). 12 d ,13 The reagents 1a – c and precursor 3 were prepared on a multigram scale as bench-stable colorless solids. According to the TG/DTA analysis, 1a – d were stable even above 200 °C.…”

Conversion of a AuI Fluorido Complex into an N‐Fluoroamido Derivative: N−F versus Au−N Reactivity

“…The latter exhibits a triplet in the 19 F NMR spectrum at −49.5 ppm with a coupling constant of 3 J HF =40 Hz due to the coupling to the CH 2 group. The amide transfer was also possible on using a bromobenzyl organyl as it was demonstrated by treatment of 2 with 4‐chlorobenzylbromide yielding (4‐chlorobenzyl)N(F)SO 2 Ph and [Au(Br)(SPhos)] [31] . No reaction was observed with methyl fluoride or benzyl fluoride.…”

“…The amide transfer was also possible on using a bromobenzyl organyl as it was demonstrated by treatment of 2 with 4‐chlorobenzylbromide yielding (4‐chlorobenzyl)N(F)SO 2 Ph and [Au(Br)(SPhos)]. [31] No reaction was observed with methyl fluoride or benzyl fluoride. Note that F 2 gas is commonly necessary to fluorinate secondary amines, for example for the synthesis of NFSI or H 3 CN(F)SO 2 Ph.…”

Conversion of a AuI Fluorido Complex into an N‐Fluoroamido Derivative: N−F versus Au−N Reactivity

“…The amide transfer was also possible on using a bromobenzyl organyl as it was demonstrated by treatment of 2 with 4chlorobenzylbromide yielding (4-chlorobenzyl)N(F)SO 2 Ph and [Au(Br)(SPhos)]. [31] No reaction was observed with methyl fluoride or benzyl fluoride. Note that F 2 gas is commonly necessary to fluorinate secondary amines, for example for the synthesis of NFSI or H 3 CN(F)SO 2 Ph.…”