Studies on the Nuclear Magnetic Resonance Spectra of (E)-1-Aryl-3-(2- and 3-thienyl)-2-propenones and Unique Observation of<sup>4</sup>J and<sup>5</sup>J Coupling in Their<sup>1</sup>H-<sup>1</sup>H COSY
作者:In-Sook HanLee、Hyun-Ju Jeon、Chang-Kiu Lee
DOI:10.5012/bkcs.2011.32.2.687
日期:2011.2.20
$^1H$ and $^13}C$ NMR spectra of series of (E)-1-aryl-(2- and 3-thienyl)-2-propenones, that are aldol condensation products between 2- and 3-thiophenecarbaldehydes and m- and p-substituted acetophenones, were examined to make complete assignments of the chemical shifts. Long range couplings, $^4J$ and $^5J$, are observed in the $^1H-^1H$ COSY of both 2- and 3-thienyl compounds, which makes the elucidation of the conformation in solution possible. In contrast, the 2-furyl analogue shows the long range coupling phenomena, but the 3-furyl and phenyl analogues do not show similar phenomena.
Novel One-Step Synthesis of Thiazolo[3,2-<i>b</i>]1,2,4-triazoles
作者:Alan R. Katritzky、Alfredo Pastor、Michael Voronkov、Peter J. Steel
DOI:10.1021/ol990370w
日期:2000.2.1
[reaction: see text] Reactions of chalcones 3a-f with bis(1H-1,2,4-triazolyl) sulfoxide 4 formed the thiazolo[3,2-b]1,2,4-triazoles 5a-f, which resemble closely some previously prepared COX-2 inhibitors. The structure of 5a was confirmed by X-ray analysis.
Nucleophilic heterocyclic carbene-catalyzed cyclopentannulation of enals and chalcones via homoenolate has been observed for the first time. Serendipitously, the reaction lead to a very efficient synthesis of 3,4-trans-disubstituted-1-aryl cyclopentenes instead of the expected cyclopentanones. The strategy works well with thienylidene tetralone also, leading to the tricyclic cyclopentene derivative
γ‐di‐aryl propanones. The salient feature of this strategy involves the sequential hydride transfer, regiospecific condensation, regiospecific dearylation, and aromatization under metal‐free reaction conditions. The synthesis of unsymmetricallysubstituted triphenylenes by oxidative coupling of the synthesized 1,2,4‐triaryl benzenes has also been demonstrated.
36 Novel heterocyclic chalcone derivatives were synthesized and tested for their anti‐bacterial activity. Some compounds presented good anti‐microbial activities against Gram‐positive bacteria (including the multidrug‐resistant clinical isolates). This class of compounds presented high potency against Streptococcus mutans, among which the derivatives F2 with an MIC of 2 µg/mL was as active as the standard