Enantioselective N-Heterocyclic Carbene Catalyzed Synthesis of Functionalized Indenes
作者:Changhe Zhang、David W. Lupton
DOI:10.1021/acs.orglett.7b01981
日期:2017.9.1
An enantioselective NHC (N-heterocycliccarbene) catalyzed synthesis of indenes from bifunctional α,β-unsaturated acyl fluorides and TMS enol ethers has been discovered. The reaction has broad generality (31 examples) and proceeds with high levels of enantioselectivity (most >92:8 er). Mechanistically the reaction likely occurs via a Michael/β-lactonization/decarboxylation sequence. Derivatization
Synthesis of 3-Fluoropyridines via Photoredox-Mediated Coupling of α,α-Difluoro-β-iodoketones with Silyl Enol Ethers
作者:Sofya I. Scherbinina、Oleg V. Fedorov、Vitalij V. Levin、Vladimir A. Kokorekin、Marina I. Struchkova、Alexander D. Dilman
DOI:10.1021/acs.joc.7b02467
日期:2017.12.15
A method for the synthesis of diversely substituted 3-fluoropyridines from two ketone components is described. The reaction involves photoredox coupling of α,α-difluoro-β-iodoketones with silyl enol etherscatalyzed by fac-Ir(ppy)3 under blue LED irradiation with subsequent one-pot condensation with ammonium acetate. Based on cyclic voltammetry studies, it was determined that α,α-difluoro-β-iodoketones
Silyl enol ethers are extremely useful nucleophilic intermediates for chemical transformations because they are synthetically versatile substrates for a wide range of C–C bond-forming reactions. Here, we present a new, mild, and solvent-free procedure for the synthesis of silyl enol ethers that employs a catalytic amount of solid-supported base and an equimolar amount of N,O-(bistrimethylsilyl)acetamide
Direct synthesis of 2-arylazulenes by [8+2] cycloaddition of 2<i>H</i>-cyclohepta[<i>b</i>]furan-2-ones with silyl enol ethers
作者:Taku Shoji、Shuhei Sugiyama、Yoshiaki Kobayashi、Akari Yamazaki、Yukino Ariga、Ryuzi Katoh、Hiroki Wakui、Masafumi Yasunami、Shunji Ito
DOI:10.1039/c9cc09376a
日期:——
We developed a procedure for the direct synthesis of 2-arylazulenes, which were obtained in moderate to excellent yields, by [8+2] cycloaddition of 2H-cyclohepta[b]furan-2-ones with aryl-substituted silylenolethers. The structures of some 2-arylazulenes were clarified by single-crystal X-ray analysis. The 2-phenylazulene derivatives obtained by this study showed noticeable fluorescence in acidic
α-Thiocyanation of Carbonyl and β-Dicarbonyl Compounds Using (Dichloroiodo)benzene−Lead(II) Thiocyanate
作者:Om Prakash、Harpreet Kaur、Hitesh Batra、Neena Rani、Shiv P. Singh、Robert M. Moriarty
DOI:10.1021/jo001504i
日期:2001.3.1
combination reagent (dichloroiodo)benzene and lead(II) thiocyanate in dichloromethane effects oxidation of various enolsilylethers, ketene silyl acetals, and beta-dicarbonyl compounds, thereby providing an efficient and convenient method for alpha-thiocyanation of carbonyl and beta-dicarbonyl compounds.