Open AccessBrønsted Acid Catalyzed (4 + 2) Cyclocondensation of 3-Substituted Indoles with Donor–Acceptor Cyclopropanes
Author(s) -
Alesandere Ortega,
Uxue Uria,
Tomás Tejero,
Liher Prieto,
Efraím Reyes,
Pedro Merino,
José L. Vicario
Publication year - 2021
Publication title -
organic letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.94
H-Index - 239
eISSN - 1523-7060
pISSN - 1523-7052
DOI - 10.1021/acs.orglett.1c00470
Subject(s) - chemistry , indole test , catalysis , brønsted–lowry acid–base theory , alkylation , acceptor , combinatorial chemistry , organic chemistry , medicinal chemistry , physics , condensed matter physics
Acylcyclopropanes are employed as useful donor-acceptor cyclopropanes that undergo 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.