An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4 H -1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an S N 2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation-thionation-saponification sequence from commercially available ω-amino alcohols. The whole process is metal-free and operationally simple.
Mollo, M.C., Bisceglia, J.A., Kilimciler, N.B., Mancinelli, M., Orelli, L.R. (2020). Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4 H -1,3-thiazines. SYNTHESIS, 52(11), 1666-1679 [10.1055/s-0039-1690822].
Microwave-Assisted Synthesis of 2-Substituted 2-Thiazolines and 5,6-Dihydro-4 H -1,3-thiazines
Mancinelli M.Membro del Collaboration Group
;
2020
Abstract
An efficient and general method for the synthesis of 2-substituted thiazolines and 5,6-dihydro-4 H -1,3-thiazines is developed via microwave-assisted ring closure of ω-thioamidoalcohols promoted by ethyl polyphosphate (PPE). The cyclization reaction involves an S N 2-type mechanism and features the advantages of very short reaction times, high yields and a predictable stereochemical outcome. The acyclic precursors are prepared in high overall yields by an improved diacylation-thionation-saponification sequence from commercially available ω-amino alcohols. The whole process is metal-free and operationally simple.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
