Copper-catalyzed Pummerer type reaction of α -thio aryl/heteroarylacetates: Synthesis of aryl/heteroaryl α -keto esters
作者:Pipas Saha、Sumit Kumar Ray、Vinod K. Singh
DOI:10.1016/j.tetlet.2017.03.069
日期:2017.5
A copper catalyzed Pummerer type reaction of α-thio aryl/heteroarylacetates is described for the first time. This transformation represents a new route to synthesize α-keto esters, which are important intermediates for pharmaceuticals and organic synthesis. The reaction proceeds via in situ generation of a thionium ion that undergoes hydrolysis to furnish α-keto esters in synthetically viable yields
Fe(OTf)2 was used to catalyze the insertionreaction of α-diazocarbonyls into S–H bonds at 40 °C. A wide range of α-thioesters were obtained in yields up to 96% within 24–48 h from their corresponding α-diazoesters. A variety of thiols were used for the unprecedented insertionreaction with an α-diazoketone, leading to yields up to 85% of α-thioketones.
Preparation of Chiral Allenes through Pd-Catalyzed Intermolecular Hydroamination of Conjugated Enynes: Enantioselective Synthesis Enabled by Catalyst Design
作者:Nathan J. Adamson、Haleh Jeddi、Steven J. Malcolmson
DOI:10.1021/jacs.9b02637
日期:2019.5.29
surrogate to afford primary amines in a two-step/one-pot process. Examination of chiral catalysts revealed a high degree of reversibility in the C-N bond formation that negatively impacted enantioselectivity. Consequently, an electron-poor ferrocenyl-PHOX ligand was developed to enable efficient and enantioselective enyne hydroamination.
A Heteroleptic Dirhodium Catalyst for Asymmetric Cyclopropanation with α‐Stannyl α‐Diazoacetate. “Stereoretentive” Stille Coupling with Formation of Chiral Quarternary Carbon Centers
作者:Fabio P. Caló、Alois Fürstner
DOI:10.1002/anie.202004377
日期:2020.8.10
The heteroleptic dirhodium paddlewheel catalyst 7 with a chiral carboxylate/acetamidate ligand sphere is uniquely effective in asymmetric [2+1] cycloadditions with α‐diazo‐α‐trimethylstannyl (silyl, germyl) acetate. Originally discovered as a trace impurity in a sample of the homoleptic parent complex [Rh2((R )‐TPCP)4] (5 ), it is shown that the protic acetamidate ligand is quintessential for rendering
Synthesis of γ-Sulfur-Substituted Ketones via Rh(II)/Sc(III) a Cocatalyzed Three-Component Reaction of Diazo Compounds with Thiophenols and Enones
作者:Guolan Xiao、Chaoqun Ma、Xiang Wu、Dong Xing、Wenhao Hu
DOI:10.1021/acs.joc.7b03074
日期:2018.4.20
A facile method for the synthesis of γ-sulfur-substituted ketones is developed via a Rh(II)/Sc(III) cocatalyzed three-componentreaction of diazo compounds with thiophenols and enones. With this method, different γ-sulfur-substituted ketones were obtained in moderate to high yields with good diastereoselectivities.