Introducing an α-Keto Ester Functional Group through Pt-Catalyzed Direct C–H Acylation with Ethyl Chlorooxoacetate
Introducing an α-Keto Ester Functional Group through Pt-Catalyzed Direct C–H Acylation with Ethyl Chlorooxoacetate
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DOI：
10.1021/acsomega.0c00982
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发表时间：
2020-04
期刊：
影响因子：
4.1
通讯作者：
Erman Javed;Jacob D. Guthrie;Justin Neu;George S. Chirayath;Shouquan Huo
中科院分区：
文献类型：
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作者：
Erman Javed;Jacob D. Guthrie;Justin Neu;George S. Chirayath;Shouquan Huo
铂催化的2-芳氧基吡啶与氯代乙酸乙酯的选择性C-H酰化反应提供了引入α-酮酯官能团的有效途径。该反应不含氧化剂，不含添加剂，更重要的是，不含任何脱羰基副反应。该反应容许从强供电子基团到强吸电子基团的各种取代基。对帕拉只有一个取代基的2-苯氧基吡啶及其衍生物，双酰化反应是可行的。虽然2-（2-甲基苯氧基）吡啶与乙基丙二酰氯的反应没有产生所需的β-酮酯，但与乙基琥珀酰氯的反应顺利进行，得到γ-酮酯。在该Pt催化的C-H酰化反应中，氯代乙酸乙酯的反应性比琥珀酰氯乙酯高得多。
Platinum-catalyzed selective C–H acylation of 2-aryloxypyridines with ethyl chlorooxoacetate provides an efficient way of introducing an α-keto ester functional group. The reaction is oxidant-free, additive-free, and, more significantly, free of any decarbonylative side reactions. The reaction tolerates a variety of substituents from strongly electron-donating to strongly electron-withdrawing groups. Double acylation is feasible for 2-phenoxypyridine and its derivatives with only one substituent at the para position. Although the reaction of 2-(2-methylphenoxy)pyridine with ethyl malonyl chloride did not produce the desired β-keto ester, the reaction with ethyl succinyl chloride proceeded smoothly to give the γ-keto ester. Ethyl chlorooxoacetate is much more reactive than ethyl succinyl chloride in this Pt-catalyzed C–H acylation reaction.