Difluorocarbene‐Induced Ring Opening of Tetrahydrofuran with TMSCF₂Br for Difluoromethoxybutylation of N‐Aryl‐N‐hydroxylamines

Abstract

In this work, a novel difluorocarbene‐induced ring opening of THF with TMSCF2Br for difluoromethoxybutylation of N‐aryl‐N‐hydroxylamines under mild conditions is reported. The mechanism study revealed that THF was intermolecular activated by difluorocarbene, then the formed oxonium ylide was nucleophilic attacked by N‐aryl‐N‐hydroxylamines.

Nitro-sulfinate Reductive Coupling to Access (Hetero)aryl Sulfonamides

“…The title compound was prepared according to a literature procedure. 22 A mixture of phenylhydroxylamine (109 mg, 1.0 mmol), NaHCO 3 (200 mg, 1.2 mmol), and 4-fluorobenzenesulfonyl chloride (464 mg, 1.2 mmol) in THF (10 mL) was stirred at room temperature for 2 h. Water (10 mL) was added, and the mixture was extracted with EtOAc (3 × 30 mL). The combined organic layers were dried over Na 2 SO 4 , filtered, and concentrated under reduced pressure.…”

Mechanochemical Difluoromethylations of Alcohols

“…Besides the synthesis of alkyl difluoromethyl ethers through the reaction of alcohol with difluorocarbene or CF 2 H + , stepwise approaches from alcohols via thioformates (Scheme 1b) 31,32 or more recently, difluorocarbene-induced ring-openings of cyclic ethers with various nucleophiles have been developed (Scheme 1c). [33][34][35] In general, however, the stepwise methods suffer from a rather small substrate scope and the requirement of multiple purifications, along with product structures of difluoromethyl ethers obtained by ring-opening of cyclic ethers being limited by ring size and nucleophile.…”