Conversion of thioamides and N 2-acyl-N 1-methyl-N 1-thioacylhydrazines into amides and N 1 N 2-diacyl-N 1-methylhydrazines by trimethyloxonium fluoroborate
Reactions of Hexadehydro-Diels–Alder (HDDA)-Derived Benzynes with Thioamides: Synthesis of Dihydrobenzothiazino-Heterocyclics
作者:Vignesh Palani、Junhua Chen、Thomas R. Hoye
DOI:10.1021/acs.orglett.6b03199
日期:2016.12.16
Reaction of thioamides (e.g., II) with benzynes generated by the hexadehydro-Diels–Alder (HDDA) cycloisomerization (e.g., I) produces dihydrobenzothiazines (e.g., III). It is postulated that the reaction proceeds via benzothietene (cf. IV) and o-thiolatoaryliminium (cf. V) intermediates and that the latter undergoes intramolecular 1,3-hydrogen atom migration to produce the penultimate isomeric iminium
Rhodium-catalyzed Direct Coupling of Benzothioamides with Alkenes and Alkynes through Directed C–H Bond Cleavage
作者:Yuki Yokoyama、Yuto Unoh、Rebekka Anna Bohmann、Tetsuya Satoh、Koji Hirano、Carsten Bolm、Masahiro Miura
DOI:10.1246/cl.150444
日期:2015.8.5
Rhodium-catalyzed direct coupling of benzothioamides with alkenes proceeds smoothly involving ortho-C–H bond cleavage. The thioamides also couple with alkynes under similar conditions accompanied b...
Several straightforward and practical processes have been established for the construction of 2-aminothiazoles, 1,3-thiazoles and 1,3-selenazoles from aryliodoazides. These strategies successfully proceed with a wide spectrum of substituted thioamides and its derivatives producing the resulting five-membered heterocycles obtained in satisfactory yields. The unique features of these protocols are operational
Conformational equilibria and torsional barriers of the isopropyl groups inN,N-diiso-propylbenzamide and its thio and seleno analogues
作者:Ulf Berg、Ingrid Pettersson
DOI:10.1002/mrc.1260230711
日期:1985.7
The conformations of the isopropyl groups and the barriers to conformational interconversion in N,N-diiso-propylbenzamide (1), and its thio (2) and seleno (3) analogues have been studied by dynamic 1H NMR spectroscopy. In 1 only one conformation is observed, whereas 2 and 3 exist as mixtures of three conformations. The use of the strongly deshielding CX (X = O, S, Se) group and comparison with earlier results on similar systems allows total assignment, in the case of 2, rectifying an earlier proposal. The temperature dependence of the NMR spectra of 2 and 3 clearly shows that the E- and Z-isopropyl groups rotate with very different rates, thus providing experimental evidence for the stepwise nature of the conformational interchange.