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BCl 3 ‐Mediated Ene Reaction of Sulfur Dioxide and Unfunctionalized Alkenes
Author(s) -
Marković Dean,
Volla Chandra M. R.,
Vogel Pierre,
VarelaÁlvarez Adrián,
Sordo José A.
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.201000164
Subject(s) - sulfinic acid , chemistry , sulfonyl , silylation , electrophile , nucleophile , reagent , organic chemistry , solvent , ene reaction , alkene , catalysis , alkyl
The first ene reactions of SO 2 and unfunctionalized alkenes are reported. Calculations suggest that the endergonic ene reactions of SO 2 with alkenes can be used to generate β,γ‐unsaturated sulfinyl and sulfonyl compounds. Indeed, in the presence of one equivalent of BCl 3 , the unstable sulfinic acid form stable sulfinic acid⋅BCl 3 complexes that can be reacted in situ with NCS to generate corresponding sulfonyl chlorides, or with a base to generate corresponding sulfinates. The latter can be reacted with electrophiles to generate sulfones, or with silyl chloride to form β,γ‐unsaturated silyl sulfinates. The sulfinic acid⋅BCl 3 complexes can be reacted with ethers that act as oxygen nucleophiles to produce corresponding sulfinic esters. Thus one‐pot, three‐component synthesis of β,γ‐unsaturated sulfonamides, sulfinyl esters and sulfones have been developed starting from alkenes and sulfur dioxide (reagent and solvent).