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Synthesis of N ‐Alkyl and N‐H ‐Carbazoles through S N Ar‐Based Aminations of Dibenzothiophene Dioxides
Author(s) -
Kaga Atsushi,
Nogi Keisuke,
Yorimitsu Hideki
Publication year - 2019
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.201903916
Subject(s) - dibenzothiophene , alkyl , chemistry , medicinal chemistry , organic chemistry , sulfur
Alkyl amines have become available for the synthesis of diverse N ‐alkyl carbazoles through twofold S N Ar aminations of dibenzothiophene dioxides by using alkali metal bases. Of particular importance is the choice of counter cations on alkali metal bases, that is, i) the use of Li base for the efficient intermolecular reaction and ii) the sequential addition of heavier alkali metal bases (Na, K, or Cs) to promote intramolecular cyclization in a one‐pot manner. This protocol also enables the cascade synthesis of N‐H ‐carbazoles by using 2‐phenylethylamine by removal of the 2‐phenethyl group from N‐ (2‐phenethyl) carbazoles in a single operation.