Metal-Free<i>meta</i>-Selective Alkyne Oxyarylation with Pyridine<i>N</i>-Oxides: Rapid Assembly of Metyrapone Analogues
作者:Xiangyu Chen、Stefan A. Ruider、Rolf W. Hartmann、Leticia González、Nuno Maulide
DOI:10.1002/anie.201607988
日期:2016.12.5
An efficient metal‐free oxyarylation of electron‐poor alkynes with pyridine N‐oxides has been developed. This transformation affords meta‐substituted pyridines analogous to the drug metyrapone in high regioselectivities. Density functional theory (DFT) calculations provided important insight into the mechanism. Evaluation of the inhibitory properties revealed the most active CYP11B1 inhibitor of these
Fast sulfonylation of pyridine/quinoline N-oxides induced by iodine is demonstrated herein. The regioselective protocol occurs under metal-free conditions in a short reaction time (10 min), exhibiting high efficiency (up to 92% yield) and good compatibility (up to 33 examples). A gram-scale reaction was conducted with only a slight loss of production.
Gold-Catalyzed Oxidative Hydrative Alkenylations of Propargyl Aryl Thioethers with Quinoline <i>N</i>-Oxides Involving a 1,3-Sulfur Migration
作者:Sachin Bhausaheb Wagh、Rahulkumar Rajmani Singh、Rajkumar Lalji Sahani、Rai-Shung Liu
DOI:10.1021/acs.orglett.9b00705
日期:2019.4.19
This work reports gold-catalyzed oxidative alkenylations of quinoline N-oxides with propargyl aryl thioethers to afford 3-hydroxy-1-alkylidenephenylthiopropan-2-one via a 1,3-sulfur group migration. The mechanism of this reaction is postulated to involve an α-oxo gold carbene intermediate followed by formation of a four-membered sulfonium ring that is ring-opened by one H2O to form a gold enolate. A
Gold-catalyzed α-furanylations of quinoline N-oxides with alkenyldiazo carbonyl species
作者:Vinayak Vishnu Pagar、Rai-Shung Liu
DOI:10.1039/c5ob00696a
日期:——
Gold-catalyzed α-furanylations of 8-alkylquinoline N-oxides have been achieved using alkenyldiazo carbonyl species as nucleophiles. The reactions are applicable to a reasonable range of alkenyldiazo species and 8-alkylquinoline N-oxides. The reaction mechanism is postulated to involve an initial nucleophilic addition of diazocarbonyl species at 8-alkylquinoline N-oxides, followed by diazo decomposition.
Gold-Catalyzed Oxidative Cycloadditions to Activate a Quinoline Framework
作者:Deepak B. Huple、Satish Ghorpade、Rai-Shung Liu
DOI:10.1002/chem.201302533
日期:2013.9.23
gold! Gold‐catalyzed reactions of 3,5‐ and 3,6‐dienynes with 8‐alkylquinoline oxides results in an oxidative cycloaddition with high stereospecificity (see scheme; EWG = electron‐withdrawing group); this process involves a catalytic activation of a quinoline framework. The reaction mechanism involves the intermediacy of α‐carbonyl pyridinium ylides (I) in a concerted [3+2]‐cycloaddition with a tethered