Fluorine in Small Molecules: Fluoromethyl Azide and Chalcogenocyanates

Abstract

Fluoromethylating agents are a highly studied and controversely discussed class of compounds. New fluoromethyl pseudohalides FCH2N3, FCH2SCN, and FCH2SeCN were prepared for the first time and their physical and spectroscopic properties investigated. Their synthesis is performed conveniently by fluoromethylation of the respective silver or potassium pseudohalogenides with fluoroiodomethane.

New Strategies for the Synthesis of Aliphatic Azides

“…307 While Karaghiosoff et al prepared from the reaction of freshly prepared silver azide with fluoroiodomethane 331 (Scheme 79c). 308 The same group reported the straightforward synthesis of 1-azido-2-bromo-1,1,2,2-tetrafluoroethane 333 from 1,2-dibromotetrafluoroethane 332 and sodium azide promoted by turbo Grignard reagent (i-PrMgCl•LiCl). Mechanistically, this transformation involves the bromophilic attack of turbo Grignard reagent could promote the elimination of bromide ion to form tetrafluoroethylene 332− 2 and subsequent anion chain reactions leading to the final product (Scheme 79d).…”

“…Following this work, they have prepared and isolated the volatile azidofluoromethane 330 by the nucleophilic substitution of bromofluoromethane 329 with sodium azides under low-temperature vacuum distillation with THF solvent (Scheme b) . While Karaghiosoff et al prepared from the reaction of freshly prepared silver azide with fluoroiodomethane 331 (Scheme c) . The same group reported the straightforward synthesis of 1-azido-2-bromo-1,1,2,2-tetrafluoroethane 333 from 1,2-dibromotetrafluoroethane 332 and sodium azide promoted by turbo Grignard reagent ( i -PrMgCl·LiCl).…”

Fluoroiodomethane: A CH2F‐Moiety‐Delivering Agent Suitable for Nucleophilic‐, Electrophilic‐, and Radical‐Harnessed Operations

“…[80] Similarly, the synthesis of fluoromethyl pseudohalides -FCH 2 N 3 , FCH 2 SCN and FCH 2 SeCN -was conveniently performed by fluoromethylation of the corresponding silver or potassium pseudohalogenides using fluoroiodomethane. [81] Previously, Gladysz reported the preparation of the rhenium α-fluoromethyl complex (CO) 5 ReCH 2 F starting from fluoroiodomethane and the strongly nucleophilic carbonyl metallate Na[Re(CO) 5 ] (Scheme 24). [82] A similar rationale has been applied by Karaghiosoff for preparing the electrophilic agent fluoromethyl-2,4,6-trinitrophenyl sulfonate, able to transfer the CH 2 F group to substrates such as carbonic acid amides, phosphorous chalcogenides, and amino groups embodied in aromatic ketones (e. g. Michler-type and ketone and dipyridyl ones) (Scheme 25).…”

“…Recently, Karaghiosoff and co‐workers investigated the reactivity of fluoroiodomethane towards highly energetic metal salts, enabling the access to the shock sensitive agent fluoromethyl perchlorate (FCH 2 OClO 3 , FMP) by treatment with anhydrous AgClO 4 , [79] and fluoromethylnitrate (FCH 2 ONO 2 ) via a silver‐catalyzed heterolysis with AgNO 3 [80] . Similarly, the synthesis of fluoromethyl pseudohalides – FCH 2 N 3 , FCH 2 SCN and FCH 2 SeCN – was conveniently performed by fluoromethylation of the corresponding silver or potassium pseudohalogenides using fluoroiodomethane [81] …”