Switching Selectivity of α-Enolic Dithioesters: One Pot Access to Functionalized 1,2- and 1,3-Dithioles.
An operationally simple cascade protocol has been developed for the construction of 1,2- and 1,3-dithiole derivatives from α-enolic dithioesters. 1,2-Dithioles are achieved by the reaction of dithioesters with elemental sulfur in the presence of InCl3under 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 1,2- and 1,3-dithioles from α-enolic dithioesters have been suggested.
Department of Chemistry, Institute of Science, Banaras Hindu University , Varanasi 221005, India.
Suvajit
S
Koley
Department of Chemistry, Institute of Science, Banaras Hindu University , Varanasi 221005, India.
Tanmoy
T
Chanda
Department of Chemistry, University Colleges of Science and Technology, University of Calcutta , 92, A.P.C. Road, Kolkata 700009, India.
Subhasis
S
Samai
Department of Chemistry, Institute of Science, Banaras Hindu University , Varanasi 221005, India.
Maya Shankar
MS
Singh