Copper-catalyzed synthesis of allenylboronic acids. Access to sterically encumbered homopropargylic alcohols and amines by propargylboration
作者:Jian Zhao、Sybrand J. T. Jonker、Denise N. Meyer、Göran Schulz、C. Duc Tran、Lars Eriksson、Kálmán J. Szabó
DOI:10.1039/c7sc05123a
日期:——
ketones and imines without any additives. Catalytic asymmetric propargylborylation of ketones is demonstrated with high stereoselectivity allowing for the synthesis of highly enantioenriched tertiary homopropargyl alcohols. The reaction is suitable for kinetic resolution of racemic allenylboronic acids affording alkynes with adjacentquaternarystereocenters.
Palladium-Catalyzed Propargylic Substitution with Phosphorus Nucleophiles: Efficient, Stereoselective Synthesis of Allenylphosphonates and Related Compounds
A new, efficient method is developed, based on a palladium(0)-catalyzedreaction of propargylic derivatives with various phosphorus nucleophiles, to produce allenylphosphonates and their analogues with defined stereochemistry in the allenic and the phosphonate moiety.
Palladium-Catalyzed Cyclization Reactions of 2,3-Allenyl Amines with Propargylic Carbonates
作者:Juntao Ye、Suhua Li、Shengming Ma
DOI:10.1021/ol3007293
日期:2012.5.4
A highly efficient and atom-economic route to synthesize 5-(1,3,4-alkatrien-2-yl)oxazolidin-2-ones via palladium-catalyzed cyclization reactions of 2,3-allenyl amines with propargylic carbonates was reported. The CO2 generated in situ from propargylic carbonates is incorporated into the oxazolidin-2-one unit with high efficiency, affording the products in 70–92% yields.
Gorlos-phos: addressing the stereoselectivity in palladium-catalyzed exo-mode cyclization of allenes with a nucleophilic functionality
作者:Juntao Ye、Suhua Li、Shengming Ma
DOI:10.1039/c3ob40983j
日期:——
A novel catalyst system has been indentified for addressing the long-standing issue of Z/E stereoselectivity in palladium-catalyzed exo-mode cyclization reactions of allenes bearing a nucleophilic functionality with organic halides or their equivalents. The readily accessible, sterically hindered monophosphine ligand Gorlos-Phos·HBF444 imparts a remarkable stereocontrolling ability with broad generality under Pd catalysis.
Palladium-Catalyzed Reaction of Propargylic Carbonates with Benzyne
作者:Shengming Ma、Shengjun Ni、Wei Shu
DOI:10.1055/s-0033-1339861
日期:——
Under the catalysis of palladium acetate, 1,2-allenyl-palladium formed from propargylic carbonates may react with two molecules of benzyne to afford phenanthrene derivatives by cyclization and beta-H elimination.