1,4-Dithiane-2,5-diol as an efficient synthon for a straightforward synthesis of functionalized tetrahydrothiophenes via sulfa-Michael/aldol-type reactions with electrophilic alkenes

Catalyst-free synthesis of trisubstituted tetrahydrothiophenes in water via a cascade sulfa-Michael/aldol (Henry) type reaction

“…For the reactions between chalcones and 1,4-dithiane-2,5-diol, the only one reference is about asymmetric catalysis using a chiral bifunctional squaramide as a catalyst to synthesize enantioenriched trisubstituted tetrahydrothiophenes. 9,16,20 From the comparison, it could be seen that the reactions under the present catalyst-free conditions generally obtained similar yields with higher diastereoselectivities than the previously reported reactions catalyzed by chiral bifunctional squaramide, Et 3 N and tertiary amine immobilized ber, respectively. 9,16,20 From the comparison, it could be seen that the reactions under the present catalyst-free conditions generally obtained similar yields with higher diastereoselectivities than the previously reported reactions catalyzed by chiral bifunctional squaramide, Et 3 N and tertiary amine immobilized ber, respectively.…”

“…1,[4][5][6][7] The tetrahydrothiophene moiety is the core structural component of many natural products, bioactive compounds and important synthetic intermediates that form thiophene derivatives through dehydration and aromatization. 2,3,[16][17][18][19][20][21] However, all these methods required catalysts. 1).…”

A one-pot synthesis of 3-nitrothiophene and 3-nitro-2-substituted thiophenes

“…The previously described microwave based approach 9 involved the preparation of a tetrahydrothiophene (THT) by treatment of 1,4-dithiane-2,5-diol 2, a dimeric mercaptoacetaldehyde equivalent 10 with 20 mol% of triethylamine and a nitroalkene (NA) in dichloromethane.…”

1,4‐Dithiane‐2,5‐diol: An Attractive Platform for the Synthesis of Sulfur‐Containing Functionalized Heterocycles

“…[8] Indeed, the sulfa-Michael/aldol reaction sequence carried out in dichloromethane with catalytic triethylamine (5 mol-%) proceeded smoothly and led to the formation in good yield (75 %) of a 3:1 mixture of the diastereomeric hexahydrobenzothiophen-4-ones 18 and 19. [8] Indeed, the sulfa-Michael/aldol reaction sequence carried out in dichloromethane with catalytic triethylamine (5 mol-%) proceeded smoothly and led to the formation in good yield (75 %) of a 3:1 mixture of the diastereomeric hexahydrobenzothiophen-4-ones 18 and 19.…”