A Study on the Activation of Carboxylic Acids by Means of 2-Chloro-4,6-dimethoxy-1,3,5-triazine and 2-Chloro-4,6-diphenoxy-1,3,5-triazine
摘要:
Activation of carboxylic function by means of 2-chloro-4,6-disubstituted-1,3,5-triazines 1 and 2 leading to triazine esters was found to be a multistep process with participation of quarternary triazinylammonium salts 3-6 as the intermediates, with the rate of reaction strongly dependent on the structure of the tertiary amine. The studies on alkylation of tertiary amines with CDMT revealed the two-step process A(N) + D-N, and zwitterionic addition product 9 was identified by H-1 NMR spectroscopy. Semiempirical modeling of the reaction as well as measured nitrogen and chlorine isotope effects also support this mechanism.
A palladium-catalyzed one-pot procedure for the synthesis of aryl ketones has been developed. Triazine esters when coupled with aryl boronic acids provided aryl ketones in moderate to excellent yields (up to 95%) in the presence of 1 mol % Pd(PPh3)2Cl2 for 30 min.
A convenient one-pot synthesis of 1,2,4-oxadiazoles is described. The condensation of carboxylic acids and amidoximes in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and N-methylmor...
Recyclable palladium-catalyzed Suzuki coupling of aromatic triazine esters: A practical one-pot synthesis of aryl ketones from aromatic acids
作者:Mingzhong Cai、Gang Xie、Zhaotao Xu、Bin Huang
DOI:10.1080/00397911.2022.2070766
日期:2022.4.3
palladium-catalyzed Suzuki coupling of aromatic triazine esters with arylboronic acids has been developed. The reaction proceeds smoothly in toluene at 110 °C using 2 mol% of MCM-41-bound bidentate phosphine palladium complex [MCM-41-2P-Pd(OAc)2] as catalyst and provides a novel and practical method for the synthesis of aryl ketones starting from readily available aromatic acids in a one-pot procedure with