Shang Rui, Fu Yao, Li Jia-Bin, Zhang Song-Lin, Guo Qing-Xiang, Liu Lei
Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
J Am Chem Soc. 2009 Apr 29;131(16):5738-9. doi: 10.1021/ja900984x.
Pd-catalyzed decarboxylative cross-coupling of aryl iodides, bromides, and chlorides with potassium oxalate monoesters has been discovered. This reaction is potentially useful for laboratory-scale synthesis of aryl and alkenyl esters. Bulky, electron-rich bidentate phosphine ligands are preferred in the reaction, whereas Cu is not needed for decarboxylation. Theoretical calculations suggest a five-coordinate Pd(II) transition state for decarboxylation with an energy barrier of approximately 30 kcal/mol.
已发现钯催化芳基碘化物、溴化物和氯化物与草酸单酯钾的脱羧交叉偶联反应。该反应对于芳基酯和烯基酯的实验室规模合成可能有用。反应中优选使用位阻大、富电子的双齿膦配体，而脱羧反应不需要铜。理论计算表明脱羧反应的五配位钯（II）过渡态的能垒约为30千卡/摩尔。
