Reactivity and diastereoselectivity of Michael additions of amines to achiral α,β-unsaturated thioamides

Secondary thioamide group deformations in different surroundings: The case of intramolecular NH···N hydrogen bond – An X-ray study combined with theoretical calculations

“…A common feature of 1t, 3t, 4t, 6 and 1c is a phenyl substituent at the thioamide group and the X-ray data confirm spectroscopic results on the orientation of thioamide and piperidine/morpholine substituents with respect to cyclohexane or cyclopentane rings [4]. In 1t both substituents are equatorially oriented, so this secondary thioamide can be formally regarded as a trans-1,2-disubstituted cyclohexane The same trans-orientation of substituents has been found in 3t and 4t.…”

“…The compounds were synthesized as described earlier [4]. Crystals of 1t and 2c were grown by slow evaporation from acetone solutions.…”

“…Recently, the Michael addition of heterocyclic, aliphatic amines to a,b-unsaturated thioamides was reported [4]. The reaction products, b-amino-functionalized secondary and tertiary thioamides, were extensively studied in solutions using NMR spectroscopy.…”

An Unexpected Discovery in the Willgerodt‐Kindler Reaction of Acetophenone––the Formation of the 4‐(Benzoylthio‐carbonyl)morpholine

“…It is found that the acetophenone disappeared after refluxing the reaction mixture in dry pyridine for 32 h (TLC monitors the reaction), however, in the case of no pyridine the reaction was completed in 20 h. Chromatographic separation of the resultant afforded compounds 1 (colorless crystal) and 2 (yellow crystal), which were turned out to be 4-(benzylthiocarbonyl)morpholine (1) and 4-(benzoylthiocarbonyl)morpholine (2) (Scheme 1) based on IR, 1 H NMR and MS spectral data. In order to confirm the structure of the unexpected product 2, the X-ray analysis was carried out.…”

“…They are of both academic and industrial interest due to their stability, odorless and easy preparation. 1 Recently, some thioamides have been found to have wide bioactivities, and used as anti-inflammatary, fungistatic reagents 2 and chain terminators in Sanger-DNA sequencing 3 reaction. Thioamides are more reactive than the corresponding amides due to its lower electronegativity and the special electronic structure of the sulfur atom.…”