The electrochemical reduction of N-fluorourethans in acetonitrile. The generation of carbethoxynitrene

Abstract

The electrochemical reduction of N-fluoro-N-methylurethan ( l a ) and N-fluorourethan (2tr) in acctonitrile gcnerates the amidc anion and a fluoride ion. Both the fluoride and thc amide anion can rcact with the starting N-fluoroamidc cither as bascs or as nucleophilcs. Many products are formcd and the coulonictric results are low (0.5 to 0.7 F/rnol). In thc case of NFU (2g), abstraction of the proton on nitrogen both by the urethan anion and the fluoridc anion generatcs thc conjugate base EtOCONF (7) which immediatcly undergoes a-elimination of the fluoride ion to givc carbethoxynitrene (11). This nitrcne was gencpted also by treating NFU (20) with a base such as tricthylamjne or lithium hydride. The a-elimination of F From EtOCONF is much casier than the a-elimination of Cl-from EtOCONCI.JEAN LESSARD et DENIS BERUBE. Can. J. Chcm. 62. 768 (1984).La rkduction Clcctrochimique du N-fluoro-N-mkthylurithane (In) ct du N-fluorourkthanc (20) conduit $

Ethyl Nosyloxycarbamate: A Chameleonic Aminating Agent

“…The product of 1,3-dipolar cycloaddition of NCO 2 Et to acetonitrile has been also observed [22]. The electrochemical reduction of ethyl N-fluorocarbamate produces (ethoxycarbonyl)nitrene and the formation of 2-ethoxy-5-methyloxadiazole from acetonitrile was compared with the reaction starting from NsONHCO 2 Et and Et 3 N [23]. In addition, the reaction with polyfluoro unsaturated compounds has been reported (Scheme 4) [24,25].…”

N‐chloro amides, lactams, carbamates, and imides. New classes of initiators for the metal‐catalyzed living radical polymerization of methacrylates

“…As a result, the N‐centered radicals are prone to undergo easier H‐abstraction and reduction reactions 80, 81, 88, 89. These aspects are well documented in the literature 64, 91, 92. In addition, N‐centered radicals undergo rearrangement reactions.…”

“…CS σ‐bond is 56.55 Kcal/mol, CN σ‐bond is 64.03 Kcal/mol, and CC σ‐bond is 72.34 kcal/mol 78. While the primary requirement for the synthesis of polymers with narrow molecular weight distributions is achieved, the quantitative initiation observed for the case of arenesulfonyl radicals9 cannot be matched by the N‐centered radicals for at least three reasons: their increased tendency to undergo dimerization,79, 80 their higher electrophilicity,80, 81 and their side reactions 82–92. The possible side reactions of N‐centered radicals are illustrated in Scheme .…”

A Class of N–O-Type Oxidants To Access High-Valent Palladium Species

“…In particular, ethyl N -methyl carbamate 7 was isolated in 27% yield, along with dimers 8 (15% yield), 9 (14% yield), and 10 (3% yield, Scheme ). The formation of these compounds was also observed when similar N -halocarbamates were exposed to electrochemical reduction conditions, via two consecutive outer-sphere single-electron transfer (SET) processes . As the 2,4-dinitrobenzenesulfonate oxidant 2c has also been used as a source for the nitrogen center radical via single-electron reduction in photochemistry and due the formation of the dimeric byproducts in the reaction conditions, we wondered if outer-sphere single-electron transfer processes are involved in the formation of our high-valent Pd intermediates.…”