Premium
Cu‐Catalyzed Aerobic Oxidative Cyclizations of 3‐ N ‐Hydroxyamino‐1,2‐propadienes with Alcohols, Thiols, and Amines To Form α‐ O ‐, S ‐, and N ‐Substituted 4‐Methylquinoline Derivatives
Author(s) -
Sharma Pankaj,
Liu RaiShung
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201406317
Subject(s) - chemistry , catalysis , nitrone , intramolecular force , molecule , medicinal chemistry , stereochemistry , organic chemistry , cycloaddition
A one‐pot, two‐step synthesis of α‐ O ‐, S ‐, and N ‐substituted 4‐methylquinoline derivatives through Cu‐catalyzed aerobic oxidations of N ‐hydroxyaminoallenes with alcohols, thiols, and amines is described. This reaction sequence involves an initial oxidation of N ‐hydroxyaminoallenes with NuH (Nu=OH, OR, NHR, and SR) to form 3‐substituted 2‐en‐1‐ones, followed by Brønsted acid catalyzed intramolecular cyclizations of the resulting products. Our mechanistic analysis suggests that the reactions proceed through a radical‐type mechanism rather than a typical nitrone‐intermediate route. The utility of this new Cu‐catalyzed reaction is shown by its applicability to the synthesis of several 2‐amino‐4‐methylquinoline derivatives, which are known to be key precursors to several bioactive molecules.