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
Palladium-Catalyzed Synthesis of 9-Fluorenylidenes through Aryne Annulation
作者:Shilpa A. Worlikar、Richard C. Larock
DOI:10.1021/ol900554r
日期:2009.6.4
The palladium-catalyzedannulation of arynes by substituted o-halostyrenes produces substituted 9-fluorenylidenes in good yields. This methodology provides this important carbocyclic ring system in a single step, which involves the generation of two new carbon−carbon bonds, occurs under relatively mild reaction conditions, and tolerates a variety of functional groups, including cyano, ester, aldehyde
A photochemicallyinduced selective and divergent cyanation reaction of alkynes, enabled by phosphorus radicals, is described. With the use of simple triarylphosphine as a co-catalyst, three cyanation reactions, including di-hydrocyanation, anti-Markovnikov hydrocyanation, and domino hydrocyanation/reduction, can be divergently achieved, furnishing a wide array of alkyl dinitriles, alkenyl nitriles
Synthesis of 9-Fluorenylidenes and 9,10-Phenanthrenes through Palladium-Catalyzed Aryne Annulation by <i>o</i>-Halostyrenes and <i>o</i>-Halo Allylic Benzenes
作者:Shilpa A. Worlikar、Richard C. Larock
DOI:10.1021/jo9017827
日期:2009.12.4
A number of functionally substituted 9-fluorenylidenes and 9,10-phenanthrenes have been synthesized from substituted o-halostyrenes and o-halo allylic benzenes respectively in good yields by the palladium-catalyzed annulation of arynes. The methodology tolerates a variety of functional groups, including cyano, ester, aldehyde, and ketone groups, occurs Under relatively mild reaction conditions, and involves the generation of two new carbon-carbon bonds, thus providing these important carbocyclic ring systems in a single synthetic step.
Polymer-Assisted horner–Emmons olefination using PASSflow reactors: pure products without purification
A PASSflow protocol for the 1-Horner-Emmons olefination of aldehydes using polymer-bound hydroxide ions in flow-through reactors is presented which allows preparation of alkenes in very high yield with minimal purification. (C) 2002 Elsevier Science Ltd. All rights reserved.