Oxidant-Assisted Sulfonylation/Cyclization Cascade Synthesis of Alkylsulfonylated Oxindoles via the Insertion of SO2.
J Org Chem
; 89(8): 5409-5422, 2024 Apr 19.
Article
em En
| MEDLINE
| ID: mdl-38563439
ABSTRACT
An oxidant-assisted tandem sulfonylation/cyclization of electron-deficient alkenes with 4-alkyl-substituted Hantzsch esters and Na2S2O5 for the preparation of 3-alkylsulfonylated oxindoles under mild conditions in the absence of a photocatalyst and transition metal catalyst is established. The mechanism studies show that the alkyl radicals, which come from the cleavage of the C-C bond in 4-substituted Hantzsch esters under oxidant conditions, subsequently undergo the in situ insertion of sulfur dioxide to generate the crucial alkylsulfonyl radical intermediates. This three-component reaction provides an efficient and facile route for the construction of alkylsulfonylated oxindoles and avoids the use of highly toxic alkylsulfonyl chlorides or alkylsulfonyl hydrazines as alkylsulfonyl sources.
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MEDLINE
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En
Ano de publicação:
2024
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Article