Open AccessUnexpected Substituent Effects in Spiro-Compound Formation: Steering N-Aryl Propynamides and DMSO toward Site-Specific Sulfination in Quinolin-2-ones or Spiro[4,5]trienones
Author(s) -
Xiaoxian Li,
Yuanxun Wang,
Yaxin Ouyang,
Zhenyang Yu,
Beibei Zhang,
Jingran Zhang,
Haofeng Shi,
Han Zuilhof,
Yunfei Du
Publication year - 2021
Publication title -
journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.2
H-Index - 228
eISSN - 1520-6904
pISSN - 0022-3263
DOI - 10.1021/acs.joc.1c00775
Subject(s) - substituent , chemistry , aryl , electrophile , intramolecular force , stereochemistry , medicinal chemistry , solvent , catalysis , organic chemistry , alkyl
A highly substituent-dependent rearrangement allows for the novel and SOCl 2 -induced divergent synthesis of 3-methylthioquinolin-2-ones and 3-methylthiospiro[4.5]trienones through intramolecular electrophilic cyclization of N -aryl propyamides. DMSO acts as both solvent and sulfur source, and use of DMSO- h 6 / d 6 enables the incorporation of SCH 3 or SCD 3 moieties to the 3-position of the heterocyclic framework. Different para -substituents trigger divergent reaction pathways leading to the formation of quinolin-2-ones for mild substituents and spiro[4,5]trienones for both electron-withdrawing and -donating substituents, respectively. On the basis of both computational and experimental results, a new mechanism has been put forward that accounts for the exclusive spirolization/defluorination process and the surprising substituent effects.