Premium
Imination of Sulfides and Sulfoxides with Sulfonylimino‐λ 3 ‐Bromane under Mild, Metal‐Free Conditions
Author(s) -
Ochiai Masahito,
Naito Masao,
Miyamoto Kazunori,
Hayashi Satoko,
Nakanishi Waro
Publication year - 2010
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.201000759
Subject(s) - chemistry , sulfur , dichloromethane , sulfoxide , sulfide , hammett equation , bromine , nucleophile , medicinal chemistry , walden inversion , aryl , stereocenter , nucleophilic substitution , metal , halogen , photochemistry , organic chemistry , alkyl , catalysis , solvent , reaction rate constant , physics , quantum mechanics , kinetics , enantioselective synthesis
Exposure of sulfides and sulfoxides to trifluoromethanesulfonylimino(aryl)‐λ 3 ‐bromane in dichloromethane at 0 °C results in a facile transfer of the sulfonylimino group to sulfur atoms and affords N ‐triflylsulfilimines and ‐ sulfoximines in high yields under transition‐metal‐free conditions. Imination of ( R )‐methyl p ‐tolyl sulfoxide proceeded with predominant retention of configuration at the stereogenic sulfur center. The Hammett plot afforded ρ values of −0.58 for para ‐substituted thioanisoles and −0.49 for their equivalent sulfoxides, which suggests a buildup of positive charge on the sulfur atoms of sulfides and sulfoxides in the transition state. Calculations suggest a bimolecular nucleophilic‐substitution mechanism on the negatively charged nitrogen atom of the sulfonylimino‐λ 3 ‐bromane, which involves the attack of a sulfide from the opposite side to bromine(III).