Captodative olefins: methyl 2-aryloxy-3-dimethyl-aminopropenoates and their application in a new synthesis of benzofurans
摘要:
The beta-substituted captodative olefins methyl 2-aryloxy-3-dimethylaminopropenoates 4a-h were synthesized, via amino-methylenation of the corresponding 2-phenoxyacetic esters 9a-h. Lewis acid promoted intramolecular cyclization of alkenes 4 led to benzofurans 7a-h, in an efficient synthetic approach to the benzofuran frame. (C) 2004 Elsevier Ltd. All rights reserved.
An efficient synthesis of benzofurans and their application in the preparation of natural products of the genus Calea
作者:María del Carmen Cruz、Joaquín Tamariz
DOI:10.1016/j.tet.2005.08.015
日期:2005.10
catalyzed by Lewis acids leads to a short and novel synthesis of benzofurans 2a–2f. When the olefins 4-dimethylamino-3-aryloxy-3-buten-2-ones 4a–4f were used, the cyclization process was faster and provided the corresponding substituted 2-acetylbenzofurans 1a–1f. Among the latter, naturally occurring compounds calebertin (1a), caleprunin A (1b), and caleprunin B (1c) were prepared in good overall yields.
Abstract An efficient and simple approach for the direct synthesis of aryl and heteroaryl sulfonic esters was developed using DMS and DES as alkoxysulfonylation reagents. The reaction is operationally simple and scalable. This protocol does not require solvent, expensive catalysts, base, ligand additives or other reagents. A wide range of sulfonic esters were synthesized in moderate to good chemical
摘要 使用 DMS 和 DES 作为烷氧基磺酰化试剂,开发了一种直接合成芳基和杂芳基磺酸酯的有效且简单的方法。该反应操作简单且可扩展。该协议不需要溶剂、昂贵的催化剂、碱、配体添加剂或其他试剂。以中等至良好的化学产率合成了多种磺酸酯。这种方法的优点是成本低、简便易行且可耐受的基材范围广。图形概要
Belleney, Joel; Vebrel, Joel; Cerutti, Ernest, Journal of Heterocyclic Chemistry, 1984, vol. 21, p. 1431 - 1435
作者:Belleney, Joel、Vebrel, Joel、Cerutti, Ernest
DOI:——
日期:——
BELLENEY, J.;VEBREL, J.;CERUTTI, E., J. HETEROCYCL. CHEM., 1984, 21, N 5, 1431-1435