Simple Gold-Catalyzed Synthesis of Benzofulvenes-<i>gem</i>-Diaurated Species as “Instant Dual-Activation” Precatalysts
作者:A. Stephen K. Hashmi、Ingo Braun、Pascal Nösel、Johannes Schädlich、Marcel Wieteck、Matthias Rudolph、Frank Rominger
DOI:10.1002/anie.201109183
日期:2012.4.27
Alkyl‐substituted diynes deliver benzofulvenes in a unique gold‐catalyzed reaction. The catalytic cycle involves the formation of gold acetylides by alkynyl C–H activation, the formation of vinylidene gold(I) intermediates by dual activation, and alkyl C–H activation by the vinylidene gold(I) species. gem‐Diaurated species obtained from the catalysis reactions prove to be highly active catalysts for
Synthesis of Spirolactones and Functionalized Benzofurans via Addition of 3-Sulfonylphthalides to 2-Formylaryl Triflates and Conversion to Benzofuroisocoumarins
作者:Deepa Nair、Pallabita Basu、Soumyaranjan Pati、Kajal Baseshankar、Chenikkayala Siva Sankara、Irishi N. N. Namboothiri
DOI:10.1021/acs.joc.2c03097
日期:——
modified Hauser–Kraus reaction of 3-sulfonylphthalide with 2-formylaryl triflates is reported here. The initial reaction involved 1,2-addition of phthalide to the formyl group and intramolecular cyclization via substitution of triflate followed by a cascade of rearrangements leading to spirolactone or benzofuran derivatives. The electronic nature of substituents on aryl triflates affected the course
本文报道了一种通过 3-磺酰苯酞与 2-甲酰芳基三氟甲磺酸酯的改良 Hauser-Kraus 反应合成螺苯并呋喃-异苯并呋喃和取代苯并呋喃的便捷方案。最初的反应涉及苯酞与甲酰基的 1,2-加成和通过取代三氟甲磺酸酯进行分子内环化,随后进行级联重排,生成螺内酯或苯并呋喃衍生物。芳基三氟甲磺酸酯上取代基的电子性质影响了反应的过程和结果。该机制得到了通过质谱法成功表征其中一种中间体的支持。一种药用相关的 B 型流感病毒抑制剂苯并呋喃异香豆素是从螺环化合物一步合成的,从而证明了我们方法的合成效用。