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Sulfinate‐Organocatalyzed (3+2) Annulation Reaction of Propargyl or Allenyl Sulfones with Activated Imines
Author(s) -
Martzel Thomas,
Lohier JeanFrançois,
Gaumont AnnieClaude,
Brière JeanFrançois,
Perrio Stéphane
Publication year - 2018
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201800749
Subject(s) - chemistry , annulation , sulfonyl , sulfone , enantiopure drug , propargyl , allene , isomerization , enantioselective synthesis , enantiomer , combinatorial chemistry , enantiomeric excess , catalysis , organic chemistry , alkyl
An operationally simple methodology for the synthesis of 4‐sulfonyl‐3‐pyrrolines is described using a propargylic sulfone and N ‐sulfonyl imines as substrates. This annulation process is initiated by an arenesulfinate organocatalyst, which allows a smooth isomerization of the alkynyl precursor into the corresponding allene, followed by the generation of a highly reactive allyl sulfone anion. An asymmetric version involving an unprecedented enantiopure sulfinate–ammonium cooperative ion pair (PhSO 2 – R 4 N + *) was investigated. A proof‐of‐concept, with enantiomeric excesses of up to 41 %, was obtained according to a preliminary screening of commercially available chiral phase‐transfer catalysts.