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Catalytic Chemoselective Sulfimidation with an Electrophilic [Co III (TAML)] − ‐Nitrene Radical Complex **
Author(s) -
Leest Nicolaas P.,
Vlugt Jarl Ivar,
Bruin Bas
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202003566
Subject(s) - nitrene , electrophile , chemistry , intramolecular force , medicinal chemistry , substituent , sulfide , photochemistry , alkyl , aryl , sigmatropic reaction , catalysis , stereochemistry , organic chemistry
The cobalt species PPh 4 [Co III (TAML red )] is a competent and stable catalyst for the sulfimidation of (aryl)(alkyl)‐substituted sulfides with iminoiodinanes, reaching turnover numbers up to 900 and turnover frequencies of 640 min −1 under mild and aerobic conditions. The sulfimidation proceeds in a highly chemoselective manner, even in the presence of alkenes or weak C−H bonds, as supported by inter‐ and intramolecular competition experiments. Functionalization of the sulfide substituent with various electron‐donating and electron‐withdrawing arenes and several alkyl, benzyl and vinyl fragments is tolerated, with up to quantitative product yields. Sulfimidation of phenyl allyl sulfide led to [2,3]‐sigmatropic rearrangement of the initially formed sulfimide species to afford the corresponding N ‐allyl‐ S ‐phenyl‐thiohydroxylamines as attractive products. Mechanistic studies suggest that the actual nitrene transfer to the sulfide proceeds via (previously characterized) electrophilic nitrene radical intermediates that afford the sulfimide products via electronically asynchronous transition states, in which SET from the sulfide to the nitrene radical complex precedes N−S bond formation in a single concerted process.