A direct C2–H thiolation of azoles with Bunte salts was achieved under the combined action of copper and silver salts, furnishing various substituted 2-thioazoles in moderate to good yields.
Organic Reactions in Ionic Liquids: An Efficient Method for Selective S‐Alkylation of 2‐Mercaptobenzothia(xa)zole with Alkyl Halides
作者:Yi Hu、Zhen‐Chu Chen、Zhang‐Gao Le、Qin‐Guo Zheng
DOI:10.1081/scc-120037917
日期:2004.12.31
(BmimPF6) and 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BmimBF4) are used as reusable reaction medium in the selective S‐alkylation of 2‐mercaptobenzothia(xa)zole with alkylhalides in the presence of potassium carbonate. This procedure is convenient, efficient, and generally gives rise to the S‐alkylated product exclusively.
catalyzed, CuII-mediated thiolation reaction between heteroarenes and thiols was achieved with good yield under base-free conditions. DMSO could serve as an effective methylthiolation reagent for the synthesis of heterocyclic methyl thioethers.
Reaction of primary or secondary 1,3-diols with dibenzoxazol-2-yl disulfide and tributylphosphine or triphenylphosphine selectively gave 2-(3-hydroxyalkylthio)benzoxazoles which, on treatment with KH, were converted into the corresponding thietanes. 2,2-Dibenzylthietane-1-oxide reacted with silylated purines and pyrimidines in the presence of TMSOTf and ZnI2 to give the corresponding thietane nucleosides in 17-69% yields.
The direct amination reaction of heterocyclic thiols has been developed in the presence of the nonhazardous photocatalyst Rose Bengal under irradiation of visible light. The reaction provides a straightforward approach to pharmaceutically and synthetically useful 2-aminobenzoxazole and 4-aminoquinazoline derivatives from the corresponding heterocyclic thiols with amines in good to excellent yields