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Studies On Palladium-Catalyzed Tadem C-H Activation/Biscyclization Reaction

Posted on:2010-02-05Degree:MasterType:Thesis
Country:ChinaCandidate:Z H RenFull Text:PDF
GTID:2121360275496022Subject:Organic Chemistry
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Palladium-catalyzed reactions is one of the most important issues in transition metal catalytic chemistry,playing a crucial role both on laboratorial synthesis and on industrial production.Pd catalysts offer an abundance of possibilities of carbon-carbon bond formation,becoming an important direction in organic synthesis. The thesis studied the mechanism of palladium-catalyzed alkynes cyclization reactions and its applications to organic synthesis.And then the thesis aims at the studies on palladium-catalyzed tandem C-H activation cyclization reactions, introducting simply its context,development and our work on it.The thesis mainly consists of the following two parts.PartⅠ:Summarized the more recent progress in palladium-catalyzed alkynes cyclization reactions.According to the reaction processes,we classified them in three types:1) cyclization viaπ-alkyne complex.2) cyclization via ~2η-alkyne-organopalladium complex.3) cyclization via allenylpalladium complex.Importantly,we introduced the progress in palladium-catalyzed cyclization reactions of propargylic compounds with nucleophiles.Through our group studied the processes of palladium catalysis reactions and the character of palladium reagent,we designed a series of palladium-catalyzed tandem cyclization reactions and got success.we mentioned our work in synthesis of indene derivatives via palladium-catalyzed cyclization reactions of propargylic carbonates containing a proximate nucleophilic center.PartⅡ:Introduced the progress in palladium-catalyzed tandem C-H activation/ biscyclization reaction and enlarged the scope of this reaction.We reported a novel tandem C-H activation/biscyclization reaction initiated by propargylic compounds with terminal alkynes.The tetracyclic benz[a]anthracene framework was high regioselective constructed by this novel reaction.This reaction constructed three C-C bonds and two carbocycles in one step.In this reaction,not only the C-H bond of benzene but simple C-C double bonds can be functionalized.Furthermore,a rational mechanism has been proposed according to the deuterium-labeling experiment.
Keywords/Search Tags:palladium-catalyzed, vinylpalladium, allenylpalladium, propargyl palladium, palladacycle intermediate, oxidative addition, C-H activation, tandem, cyclization, cross-coupling, alkyne, propargyl carbonate, carbocyclic compound, nucleophile
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