59208-12-7Relevant academic research and scientific papers
Non-dipolar behavior of mesoionic heterocycles: Synthesis and tautomerism of 2-alkylthioisomuenchnones
Avalos, Martin,Babiano, Reyes,Cintas, Pedro,Diaz, Jesus,Jimenez, Jose L.,Lopez, Ignacio,Palacios, Juan C.
, p. 2805 - 2811 (2004)
This paper describes a general preparation of a series of 1,3-thiazolium-4-olates, each bearing an alkyl group at C-2, through reactions between N-arylthiocarboxamides and α-haloacyl halides. Unlike the 2-aryl-substituted derivatives, such alkylated mesoionic compounds exist in equilibria with their non-dipolar tautomers, the corresponding 2-alkylidene-1,3-thiazolidin-4-ones. The unambiguous characterization of such tautomers and their relative stabilities have now been assessed by spectroscopic and computational studies. The presence of o,o′-disubstituted aryl groups at N-3 of the heterocyclic ring slows down free rotation around the N-Ar bond, thus opening access to a promising class of non-biaryl atropisomers. Finally, treatment of N-arylthioformamides with α-haloacyl halides gives rise to N-acylthioformamides instead of the corresponding mesoionic species. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
