Aerobic Oxidation of <i>N</i>-Alkylamides Catalyzed by <i>N</i>-Hydroxyphthalimide under Mild Conditions. Polar and Enthalpic Effects
作者:Francesco Minisci、Carlo Punta、Francesco Recupero、Francesca Fontana、Gian Franco Pedulli
DOI:10.1021/jo016398e
日期:2002.4.1
O(2), catalyzed by N-hydroxyphthalimide (NHPI) and Co(II) salt, leads under mild conditions to carbonyl derivatives (aldehydes, ketones, carboxylic acids, imides) whose distribution depends on the nature of the alkyl group and on the reaction conditions. Primary N-benzylamides lead to imides and aromatic aldehydes at room temperature without any appreciable amount of carboxylic acids, while under the
由N-羟基邻苯二甲酰亚胺(NHPI)和Co(II)盐催化的O(2)对N-烷基酰胺的氧化在温和条件下导致羰基衍生物(醛,酮,羧酸,酰亚胺)的分布取决于性质烷基的取代基和反应条件。N-苄基伯酰胺在室温下可生成酰亚胺和芳族醛,而无需添加任何量的羧酸,而在相同条件下,即使在非常低的转化率下,非苄基衍生物也可生成不含痕量醛的羧酸和酰亚胺。这些结果通过邻苯二甲酰亚胺-N-氧基(PINO)自由基的夺氢来解释,该邻苯二甲酰亚胺-N-氧基(PINO)与苄基衍生物的反应性受极性作用的支配,因此苄酰胺比相应的醛更具反应性。焓效应是,非苄基酰胺占主导地位,使相应的醛比起始酰胺更具反应性。强调了NHPI中OH键的键解离能(BDE)的重要性。