Bayer,H.O. et al., Chemische Berichte, 1970, vol. 103, p. 2581 - 2597
作者:Bayer,H.O. et al.
DOI:——
日期:——
Stepwise Formation of 1,3-Diazolium-4-thiolates by Münchnone Cycloadditions: Promising Candidates for Nonlinear Optics
作者:David Cantillo、Martín Ávalos、Reyes Babiano、Pedro Cintas、José L. Jiménez、Mark E. Light、Juan C. Palacios、Rocío Porro
DOI:10.1021/jo500349g
日期:2014.5.2
tes by [3 + 2] cycloadditions of münchnones with arylisothiocyanates is reported. The process takes place with high or complete regioselectivity, and fast and clean transformations are observed under microwave heating in DMF. DFT calculations support that this cycloaddition proceeds preferably through a stepwise mechanism. Given the pattern substitution around the mesoionic ring resulting in a push–pull
Push-pull 1,3-thiazolium-5-thiolates. Formation via concerted and stepwise pathways, and theoretical evaluation of NLO properties,
作者:David Cantillo、Martín Ávalos、Reyes Babiano、Pedro Cintas、José L. Jiménez、Mark E. Light、Juan C. Palacios、Valentín Rodríguez
DOI:10.1039/c0ob00416b
日期:——
The transformation of münchnones (mesoionic rings featuring the 1,3-oxazolium-5-olate core) into their sulfur counterparts (1,3-thiazolium-5-thiolates) by reaction with CS2, pioneered by Huisgen and his group in the early 1970s, has been re-investigated in detail by means of both experimental and theoretical methods. The synthetic strategy can be tuned to incorporate donor and acceptor groups in appropriate positions. Calculations of molecular hyperpolarizabilities together with orbital topologies evidence that these sulfur-containing heterocycles exhibit nonlinear optical responses, thereby pointing to potential applications of mesoionic structures in the NLO field. From a mechanistic viewpoint, modeling of the whole systems at the B3LYP/6-31G(d) level reveals that concerted and stepwise pathways are operative depending on the substitution pattern of the parent münchnone, which also account for the experimental results.