Palladium-catalyzed Mizoroki–Heck reactions were carried out in the presence of calcium carbonate in alcoholic solvents. Under these conditions an efficient preparation of functionalized benzalacetones was developed. The reactions were carried out at room temperature and aerobic conditions, giving the products within several minutes in up to 95% isolated yields. Furthermore, some kinetic investigations
[3 + 2] Cycloaddition of Isocyanides with Aryl Diazonium Salts: Catalyst-Dependent Regioselective Synthesis of 1,3- and 1,5-Disubstituted 1,2,4-Triazoles
作者:Jian-Quan Liu、Xuanyu Shen、Yihan Wang、Xiang-Shan Wang、Xihe Bi
DOI:10.1021/acs.orglett.8b03069
日期:2018.11.2
An unprecedented catalyst-dependent regioselective [3 + 2] cycloaddition of isocyanides with aryl diazonium salts is reported. 1,3-Disubstituted 1,2,4-triazoles were selectively obtained in high yield under Ag(I) catalysis, whereas 1,5-disubstituted 1,2,4-triazoles were formed by Cu(II) catalysis. These catalytic methodologies provide a controlled, modular, and facile access to 1,2,4-triazole scaffolds
Preparation of <i>N</i>-Arylquinazolinium Salts via a Cascade Approach
作者:Mani Ramanathan、Jing Wan、Shiuh-Tzung Liu
DOI:10.1021/acs.joc.9b00601
日期:2019.6.7
readily available aryldiazonium salts, nitriles, and 2-aminoarylketones in a one-pot operation. This method relies on the in situ generation of the N-arylnitrilium intermediate from the reaction of aryldiazonium salt with nitrile, which undergoes amination/cascade cyclization/aromatization, leading to N-arylquinazolinium salts in excellent yields. Nucleophilic addition of alkoxide to these N-arylquinazolinium