Brønsted Acid Catalyzed (4 + 2) Cyclocondensation of 3-Substituted Indoles with Donor–Acceptor Cyclopropanes
作者:Alesandere Ortega、Uxue Uria、Tomás Tejero、Liher Prieto、Efraim Reyes、Pedro Merino、Jose L. Vicario
DOI:10.1021/acs.orglett.1c00470
日期:2021.3.19
formal (4 + 2) cyclocondensation with N-unprotected 3-substituted indoles in the presence of a Brønsted acid catalyst. The reaction involves the simultaneous alkylation of both the N and C-2 positions of the indole and provides access to the 8,9-dihydropyrido[1,2-a]indole scaffold that is the central core of several biologically relevant indole alkaloids in excellent yields and good selectivities.
酰基环丙烷用作有用的供体-受体环丙烷,在布朗斯台德酸催化剂的存在下与N-未保护的 3-取代吲哚进行形式 (4 + 2) 环缩合反应。该反应涉及吲哚的 N 和 C-2 位置的同时烷基化,并提供了进入 8,9-二氢吡啶并[1,2- a ] 吲哚支架的途径,该支架是几种生物学相关的吲哚生物碱的核心收率和良好的选择性。