Synthesis of N-Arylisoindolin-1-ones via Pd-Catalyzed Intramolecular Decarbonylative Coupling of N-(2-Bromobenzyl)oxanilic Acid Phenyl Esters
作者:Wei-Min Dai、Yu Zheng、Gongli Yu、Jinlong Wu
DOI:10.1055/s-0029-1219580
日期:2010.4
Ethyl and phenyl oxanilates were readily prepared from N-(2-bromobenzyl)anilines and oxalyl chloride monoethyl and monophenyl esters, respectively. It was found that the ethyl oxanilate survived in the presence of K 2 CO 3 in DMA at 120 °C and underwent an intramolecular direct arylation using Pd(OA C ) 2 -dppf, furnishing the 5,6-dihydrophenanthridine derivative. In contrast, the corresponding phenyl
从 N-(2-溴苄基) 苯胺和草酰氯单乙基酯和单苯基酯,分别很容易制备乙基和苯基草酸酯。发现草胺酸乙酯在 DMA 中存在 K 2 CO 3 时在 120°C 下存活,并使用 Pd(OA C ) 2 -dppf 进行分子内直接芳基化,提供 5,6-二氢菲啶衍生物。相比之下,相应的苯草酰苯酯在 120 °C 的 DMA 中暴露于 K 2 CO 3 时分解,并通过 Pd(OAc) 2 -dppf 催化的分子内脱羰偶联转化为 N-芳基异吲哚啉-1-酮。除了 4-甲氧基取代的草苯二酸苯酯外,其他具有吸电子 (NO 2 , Cl) 和弱给电子 (Me) 取代基的苯草酸苯酯以 43-80% 的产率提供了 N-芳基异吲哚啉-1-酮.