B-Alkyl Suzuki couplings for the stereoselective synthesis of substituted pyrans
作者:Gregory W. O’Neil、Alois Fürstner
DOI:10.1039/b806898d
日期:——
Unprotected homoallylic alcohols can be directly converted to cis-2,6-disubstituted pyrans by palladium catalyzed B-alkyl Suzuki coupling and subsequent Michael addition.
Gold-Catalyzed Synthesis of Oxygen- and Nitrogen-Containing Heterocycles from Alkynyl Ethers: Application to the Total Synthesis of Andrachcinidine
作者:Hyung Hoon Jung、Paul E. Floreancig
DOI:10.1021/jo071225w
日期:2007.9.1
containing pendent oxygen or nitrogennucleophiles react with electrophilic gold catalysts in the presence of water to form saturated heterocyclic ketones. Mechanistic studies demonstrated that the reactions proceed through a sequence of alkyne hydration, alkoxy group elimination, and intramolecularconjugateaddition. Diastereoselectivities for tetrahydropyran and piperidine formation are very good to
Gold-Catalyzed Heterocycle Synthesis Using Homopropargylic Ethers as Latent Electrophiles
作者:Hyung Hoon Jung、Paul E. Floreancig
DOI:10.1021/ol060574u
日期:2006.4.1
Homopropargylic ethers with pendent nucleophiles, when subjected to Au catalysts in aqueous solvent, provide heterocyclic ketones. The reactions are efficient, tolerant of functionality and ambient atmosphere, and operationally simple. Diastereoselectivity can be predicted on the basis of product thermodynamics. This process demonstrates the viability of homopropargylic ethers to serve as latent electrophiles that can be unraveled under highly selective conditions to promote heterocycle formation through nucleophilic additions to alpha,beta-unsaturated ketones.
Stereoselective construction of cis-2,6-disubstituted tetrahydropyrans via an intramolecular bismuth-mediated oxa-conjugate addition reaction
作者:P. Andrew Evans、William J. Andrews
DOI:10.1016/j.tetlet.2005.06.100
日期:2005.8
The intramolecular oxa-conjugate addition of tethered triethylsilyloxy substituted alpha,beta-unsaturated ketones mediated by bismuth(III) nitrate pentahydrate provides a mild and efficient method for the stereoselective construction of cis-2,6-disubstituted tetrahydropyrans. (c) 2005 Elsevier Ltd. All rights reserved.