Switching Selectivity of α-Enolic Dithioesters: One Pot Access to Functionalized 1,2- and 1,3-Dithioles
摘要:
An operationally simple cascade protocol has been developed for the construction of 1,2- and 1,3-dithiole derivatives from alpha-enolic dithio esters. 1,2-Dithioles are achieved by the reaction of dithioesters with elemental sulfur in the presence of InCl3 under solvent-free conditions. 1,3-Dithioles have been constructed via DABCO mediated self coupling of dithioesters in open air enabling the formation of two new C-S bonds and one ring in a single operation in contiguous fashion. The reactions proceeded smoothly affording the desired sulfur-rich heterocycles in good to excellent yields, exhibiting gram-scale ability and broad functional group tolerance utilizing easy to handle cheap and easily available reagents. The probable mechanisms for the formation of suggested. 1,2- and 1,3-dithioles from alpha-enolic dithioesters have been suggested.
Convenient one-pot syntheses of 1,2-dithiole-3-thiones and 3-imino-1,2-dithioles from terminal alkynes
作者:Harry Adams、Amelia J. Hughes、Michael J. Morris、Sophia I.A. Quenby
DOI:10.1016/j.tetlet.2014.07.104
日期:2014.9
reaction of acetylide anions with carbon disulfide or phenyl isothiocyanate followed by addition of sulfur in the presence of a protonating agent such as a primary amine or alcohol affords 1,2-dithiole-3-thiones or 3-imino-1,2-dithioles in good to excellent yields.