Kinetic resolution displaying zeroth order dependence on substrate consumption: copper-catalyzed asymmetric alcoholysis of azlactones.
Kinetic resolution displaying zeroth order dependence on substrate consumption: copper-catalyzed asymmetric alcoholysis of azlactones.
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DOI：
10.1021/ja058112j
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发表时间：
2006-04
影响因子：
15
通讯作者：
M. Tokunaga;Junya Kiyosu;Y. Obora;Y. Tsuji
中科院分区：
文献类型：
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作者：
M. Tokunaga;Junya Kiyosu;Y. Obora;Y. Tsuji
用铜-4-alkyl-2-aryl-5-oxo-4，5-dihydrooxazole-4-carboxylic-SEGPHOS催化的醇解反应实现了氨内酯的动力学拆分(12例)。未反应底物1和产物2的ee随转化率的变化遵循零级动力学拆分的理论曲线，首次给出了其选择性曲线和图解分析。零级反应的拆分效率高于一级反应。例如，与1a的反应在57%的转化率下得到(S)-1a(99%ee)和(R)-2a(74%ee)，其中k(Rel)=6.7为零级动力学分辨，37为一级动力学分辨。
Kinetic resolution of 4-alkyl-2-aryl-5-oxo-4,5-dihydrooxazole-4-carboxylic acid esters (azlactones 1) were achieved by copper-DTBM-SEGPHOS catalyzed alcoholysis reaction with good selectivity (12 examples). Variation of ee of unreacted substrates 1 and products 2 with conversion was found to follow the theoretical line of zeroth-order kinetic resolution, for which the selectivity profiles and graphical analysis were presented for the first time. The efficiency of resolution in zeroth-order reaction is higher than first-order reaction. For example, the reaction with 1a afforded (S)-1a (99% ee) and (R)-2a (74% ee) at 57% conversion, where the k(rel) values were calculated to be 6.7 as zeroth-order kinetic resolution and 37 as first-order kinetic resolution.