A route to aryl-substituted quinolines from N-tosyl 1-azadienes is described. The key steps are a [4+2] cycloaddition with benzyne followed by base treatment of the 1,4-dihydroquinoline product. The N-tosyl 1-azadienes were prepared from readily accessible cinnamaldehyde and chalcone substrates by condensation with p-TsNH2. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications (R) to view the free supplemental file.
A Multicomponent Reaction of Acetals for the Preparation of Quinolines
作者:Xue-Lin Zhang、Qin-Pei Wu、Qing-Shan Zhang
DOI:10.3184/174751913x13814036942713
日期:2013.11
A straightforward, mild, one-pot method has been found for the preparation of quinolines via a multi-component reaction using acetals or cyclic acetals, aromatic amines and alkynes catalysed by Bi(OTf)3. It gives good yields under mild conditions. This approach has been successfully applied for the synthesis of a range of quinolines with a variety of functional groups.
The reaction of imines with alkynes and alkenes, in the presence of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), to give quinoline derivatives is described. The mechanism of the annulation is discussed, and evidence supporting a non-concerted pathway, at least when the alkene is butyl vinyl ether, is reported. Preliminary information is also given about solid adducts of imines with DDQ, which do
polysubstituted quinolinesfrom o-vinyl anilines and aldehydes. The reaction proceeds in a cascade manner through condensation, electrocyclization and dehydrogenation, and gives access to a wide range of quinolines with alkyl and/or aryl substituents as demonstrated with 40 examples. The metal-free catalytic procedure allows a heterogeneous protocol for the synthesis of various polysubstituted quinolines. The
one-pot approach for the synthesis of quinolines from o-aminothiophenol and 1,3-ynone under mild conditions is disclosed. With the aid of ESI-MS analysis and parallel experiments, a three-step mechanism is proposed-a two-step Michael addition-cyclization condensation step leading to intermediate 1,5-benzothiazepine catalyzed by zirconocene amino acid complex Cp2Zr(η1-C9H10NO2)2, followed by I2-mediated
Regiospecific Three-Component Access to Fluorescent 2,4-Disubstituted Quinolines via One-Pot Coupling-Addition-Cyclocondensation-Sulfur Extrusion Sequence
作者:Sven Rotzoll、Benjamin Willy、Jan Schönhaber、Frank Rominger、Thomas J. J. Müller
DOI:10.1002/ejoc.201000212
日期:——
4-Di- and 2,4,7-trisubstituted quinolines are readily synthesized in a regioselective fashion from acyl chlorides, terminal alkynes, and 2-aminothiophenols by a consecutive, microwave-assisted one-potthree-component Sonogashira coupling-Michael addition-cyclocondensation sequence and following sulfur extrusion in moderate to good yields. The terminal sulfur extrusion step was studied by DFT computations