20662-89-9Relevant articles and documents
Widely Exploited, Yet Unreported: Regiocontrolled Synthesis and the Suzuki–Miyaura Reactions of Bromooxazole Building Blocks
Solomin, Vitalii V.,Radchenko, Dmytro S.,Slobodyanyuk, Evgeniy Y.,Geraschenko, Oleksandr V.,Vashchenko, Bohdan V.,Grygorenko, Oleksandr O.
, p. 2884 - 2898 (2019/03/07)
An approach to synthesis of 2-, 4-, and 5-bromooxazoles is described. The method was optimized, and its scope was extended to all three isomeric parents, as well as various alkyl- and aryl-substituted bromooxazoles. It was found that direct regiocontrolled lithiation followed by reaction with electrophilic bromine source was common for all substrates and led exclusively to the target substituted 2-, 4- and 5-bromooxazoles on multigram scale. The utility of the multipurpose building blocks obtained in this work was demonstrated in the Suzuki–Miyaura cross-coupling reaction under parallel synthesis conditions.
Synthesis of Triarylpyridines in Thiopeptide Antibiotics by Using a C-H Arylation/Ring-Transformation Strategy
Amaike, Kazuma,Itami, Kenichiro,Yamaguchi, Junichiro
supporting information, p. 4384 - 4388 (2016/03/22)
We have described a C-H arylation/ring-transformation strategy for the synthesis of triarylpyridines, which form the core structure of thiopeptide antibiotics. This synthetic method readily gave 2,3,6-triarylpyridines in a regioselective manner by a two-p
Facile structural elucidation of imidazoles and oxazoles based on NMR spectroscopy and quantum mechanical calculations
Weitman, Michal,Lerman, Lena,Cohen, Shmuel,Nudelman, Abraham,Major, Dan T.,Gottlieb, Hugo E.
scheme or table, p. 1465 - 1471 (2010/04/04)
The reaction of 1,2,3-tricarbonyl derivatives with hexamethylenetetramine and ammonium acetate in acetic acid provides an unambiguous approach to the synthesis of imidazoles, whereas the Bredereck reaction of α-haloketones in formamide, yields both imidazoles and oxazoles. Herein we describe a facile methodology for distinguishing between these heterocyclic compounds based on a combination of NMR spectroscopy and quantum mechanical calculations. In the NMR data the oxazole C-2 has a chemical shift of ca. 150 ppm whereas in the imidazoles it is found at ca. 135 ppm, with a 1JC-H of ca. 250 Hz for the oxazoles and ca. 210 Hz for the imidazoles. 1JC-H values can be easily obtained from a gated-decoupled 13C spectrum, and even more trivially, from the separation of the H-2 13C satellites in the 1H spectra. Additionally, the computed NMR data, obtained from density functional theory, are found to be in good agreement with the experimental data and serve as valuable tools in identifying the products of the Bredereck reaction.
