One-Pot Suzuki-Hydrogenolysis Protocol for the Modular Synthesis of 2,5-Diaryltetrazoles
摘要:
2,5-Diaryltetrazoles are a diverse range of compounds of considerable interest within the field of photochemistry as a valuable precursor of the nitrile imine 1,3-dipole. Current literature approaches toward this heterocycle remain unsuitable for the practical synthesis of a library of these derivatives. Herein, we disclose the development of a modular approach toward 2,5-diaryltetrazoles compatible with an array-type protocol, facilitated by a tandem Suzuki-hydrogenolysis approach.
A novel method for the synthesis of 5-substituted 1H-tetrazoles using diphenyl phosphorazidate (DPPA) has been developed. Aromatic and aliphatic aldoximes underwent cycloaddition to afford the corresponding 5-substituted 1H-tetrazoles with ease and efficiency.
Facile one-pot preparation of 5-aryltetrazoles and 3-arylisoxazoles from aryl bromides
作者:Eiji Kobayashi、Hideo Togo
DOI:10.1016/j.tet.2018.06.044
日期:2018.8
The successive treatment of aryl bromides with n-BuLi, DMF, hydroxylaminehydrochloride, and finally diphenylphosphoryl azide provided efficiently the corresponding 5-aryltetrazoles in good to moderate yields. Similarly, the successive treatment of aryl bromides with n-BuLi, DMF, hydroxylaminehydrochloride, and finally diethyl acetylenedicarboxylate and Oxone® provided efficiently the corresponding
racemization. 5-Substituted 1H-tetrazoles were effectively synthesized from aldoximes and diphenyl phosphorazidate (DPPA) under reflux conditions in xylenes. Various aldoximes underwent the cycloaddition reaction to afford the corresponding 5-substituted 1H-tetrazoles in short reaction times and in good yields. Chiral aldoximes derived from amino acids also gave aminotetrazoles with almost no racemization.
Palladium-catalyzed stille couplings of aryl-, vinyl-, and alkyltrichlorostannanes in aqueous solution
作者:Roopa Rai、Katherine B. Aubrecht、David B. Collum
DOI:10.1016/0040-4039(95)00485-u
日期:1995.5
Stille coupling of water-soluble aryl and vinyl halides with alkyl-, aryl-, and vinyltrichlorostannane derivatives (RSnCl3) are effected in aqueous solution using a catalyst generated in situ from PdCl2 and KOH both with and without added PhP(m-C6H4SO3Na)2. The yields are generally good to excellent, although some limitations of the protocol are described.
的Stille的水溶性的芳基和乙烯基卤化物与烷基连接,芳基- ,和vinyltrichlorostannane衍生物(RSnCl 3)使用所生成的催化剂在水溶液中进行原位从的PdCl 2和KOH具有和不具有添加的PHP(米-C 6 H 4 SO 3 Na)2。尽管描述了协议的一些局限性,但收率通常良好或优异。
Development of a Chiral DMAP Catalyst for the Dynamic Kinetic Resolution of Azole Hemiaminals
作者:Artis Kinens、Marcis Sejejs、Adam S. Kamlet、David W. Piotrowski、Edwin Vedejs、Edgars Suna
DOI:10.1021/acs.joc.6b02955
日期:2017.1.20
A new catalyst for the dynamic kineticresolution of azole hemiaminals has been developed using late-stage structural modifications of the tert-leucinol-derived chiral subunit of DMAP species.