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Showing 1 to 10 of 10 for “"carbenoids"”.
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The generation and reactivity of functionalised organozinc carbenoids for cyclopropane synthesis
… and reactivity of functionalised organozinc carbenoids for cyclopropane synthesis with alkenes. In the introductory chapter, a brief overview of the different methods for preparation of heteroatom-functionalised cyclopropanes is presented, including [2+1] cycloaddition reactions using a …
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Studies towards the total synthesis of labiatin A
… Chapter I provides an introduction to metal carbenoids and their uses in organic synthesis. In particular, the synthesis of diazo carbonyl compounds, their decomposition by metal catalysts leading to the formation of metal carbenoids and the reactions involving metal carbenoids is described. …
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Carbenoid insertions and cyclometallations of zirconacycles
… of chloro(aryl)methyllithiums (benzyl carbenoids) into a range of<br/>zirconacyclopentenes and zirconacyclopentanes.<br/><br/>Benzyl carbenoid insertion into a zirconacyclopentene generated the<br/>zirconacyclohexene via a 1,2-metalate rearrangement. A low temperature …
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I Peptide isosteric replacement preparation using zinc-mediated chain extension-aldol reactions II Formal synthesis of (+)-Brefeldin A III Zinc-mediated chain extension reactions with substituted carbenoids
… a chain extension reaction using substituted carbenoids has also been accomplished.*.</p>
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Formal Insertion Reactions Of Stannylenes And Germylenes Into Phosphorus-Halogen Bonds: A Structural And Mechanistic Investigation
<p>Insertion reactions of Group 14 carbenoids, divalent species of the form (R<sub>2</sub>N)<sub>2</sub>M (M = Ge or Sn) into the P-halogen bond of halophosphines have been known for some time. However, very few examples have been reported and no evidence has been presented regarding the mechanism …
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Tandem reaction sequences on a zirconocene template
… of 1,1-dihalo-1-lithio species (dihalogenocarbenoids). Further rearrangement to a novel zirconium-alkenylidene complex driven by acetylides provided a powerful method for a rapid construction of novel bicyclic compounds with the potential for functionalization at multiple sites. Such …
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Novel titanium carbenoid reagents: diversity orientated synthesis of indoles and spirocycles
… and 1,7-dioxaspiro[5.5]undecanes). The titanium carbenoids are easily generated from readily available thioacetals.
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Construction of carbocycles via oxonium ylides generation and rearrangement: towards the synthesis of taxol
… method in which intramolecular reaction of metal carbenoids with α-vinyl ethers and subsequent [2,3]-rearrangement of the cyclic oxonium ylide intermediates has been used as a powerful strategy to produce linearly fused bicyclic and tricyclic systems. Following the success of our methodology, a …
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TEMPLATE DIRECTED C-H INSERTION REACTIONS FOR STEREOCONTROLLED SYNTHESIS OF HETEROCYCLES
… substrates representing the three classes of carbenoids were synthesised. In the foremost route that led to the first class, the diazoacetoacetates were obtained from the oxidation of the diazoketols prepared by an aldol type condensation between the aldehyde acetals and ethyldiazoacetate. …
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Exploring the reactivity of alpha-triorganylsilyl alpha-diazo esters : C-H activation, insertion reactions, and rearrangements
The metal-catalyzed reactions of Alpha-triorganylsilyl Alpha-diazo esters have been studied, with an emphasis on: · Dirhodium(II)-catalyzed insertions of Alpha-triorganylsilyl Alpha-diazo esters into activated C-H bonds. · Dirhodium(II)-catalyzed reactions of -triorganylsilyl Alpha-diazo esters …