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Organocatalytic Synthesis of gem ‐Difluorinated C2‐Spiro Indolines and Pyrimido[1,2‐ a ]benzimidazoles from 2‐Alkynyl‐3,3‐Difluoro‐3 H ‐Indoles
Author(s) -
Mao XiangYu,
Lin XiaoTong,
Yang Meng,
Chen GuoShu,
Liu YunLin
Publication year - 2018
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201800716
Subject(s) - chemistry , regioselectivity , indoline , nucleophile , functional group , benzimidazole , substrate (aquarium) , combinatorial chemistry , yield (engineering) , medicinal chemistry , catalysis , cascade reaction , stereochemistry , organic chemistry , oceanography , materials science , metallurgy , geology , polymer
In this communication, we report a substrate‐controlled product diversity in the 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD)‐catalyzed cascade cyclization of 2‐alkynyl‐3,3‐difluoro‐3 H ‐indoles with N,N ‐ or N,S ‐bis‐nucleophiles. The products represent two important heterocyclic compounds, C2‐spiro indoline, and pyrimido[1,2‐ a ]benzimidazole, featuring a versatile gem ‐difluoromethylene group on the framework. In these cascade processes, two new C−N bonds, or one C−S and one C−N bond, are consecutively formed in a single step. The present protocol is characterized with high regioselectivity, high yield, broad substrate scope, good functional group tolerance, facile scalability and mild reaction conditions.