4-Bis(methylthio)methylene-2-phenyloxazol-5-one: Versatile Template for Synthesis of 2-Phenyl-4,5-functionalized Oxazoles
摘要:
4-Bis(methylthio)methylene-2-phenyloxazol-5-one has been shown to be a versatile template for the synthesis of various 2-phenyl-3,4-substituted oxazoles via nucleophilic ring-opening of oxazolone with various oxygen, nitrogen, and carbon nucleophiles and subsequent 5-endo cyclization of the resulting acyclic adducts in the presence of silver carbonate.
Synthesis of 2,5-Bis(hetero)aryl 4′-Substituted 4,5′-Bisoxazoles via Copper(I)-Catalyzed Domino Reactions of Activated Methylene Isocyanides with 2-Phenyl- and 2-(2-Thienyl)-4-[(aryl/heteroaryl)(methylthio)methylene]oxazol-5(4<i>H</i>)-ones
作者:Somaraju Yugandar、Anand Acharya、Hiriyakkanavar Ila
DOI:10.1021/jo400317g
日期:2013.4.19
An efficient straightforward synthesis of 2,5,4′-trisubstituted 4,5′-bisoxazoles via copper(I)-catalyzed domino reactions of 2-phenyl- and 2-(2-thienyl)-4-[(aryl/heteroaryl)methylene]-5-oxazolones with activatedmethylene isocyanides has been reported. The overall domino process comprised of formation of one C–C and two C–O bonds involves initial nucleophilic ring opening of oxazolones by cupriomethylene
Synthesis of 2,4,5-Trisubstituted Thiazoles via Lawesson’s Reagent-Mediated Chemoselective Thionation–Cyclization of Functionalized Enamides
作者:S. Vijay Kumar、G. Parameshwarappa、H. Ila
DOI:10.1021/jo401208u
日期:2013.7.19
An efficient route to 2-phenyl/(2-thienyl)-5-(het)aryl/(methylthio)-4-functionalized thiazoles via one-step chemoselective thionation-cyclization of highly functionalized enamides mediated by Lawesson's reagent is reported. These enamide precursors are obtained by nucleophilic ring-opening of 2-phenyl/(2-thienyl)-4-[bis(methylthio)/(methylthio)(het)arylmethylene]-5-oxazolones with alkoxides and a variety of primary aromatic/aliphatic amines or amino acid esters, leading to the introduction of an ester, an N-substituted carboxamide, or a peptide functionality in the 4-position of the product thiazoles.