Fe(II)/Au(I) Relay Catalyzed Propargylisoxazole to Pyridine Isomerization: Access to 6-Halonicotinates
作者:Alexey V. Galenko、Firuza M. Shakirova、Ekaterina E. Galenko、Mikhail S. Novikov、Alexander F. Khlebnikov
DOI:10.1021/acs.joc.7b00736
日期:2017.5.19
An efficient synthesis of methyl nicotinates/6-halonicotinates by the domino isomerization of 4-propargyl/(3-halopropargyl)-5-methoxyisoxazoles under Fe(II)/Au(I) relay catalysis was developed. It was found that FeNTf2 is an effective catalyst for first step of the domino isomerization, transformation of isoxazole to 2H-azirine, which is compatible with Ph3PAuNTf2, catalyzing the second step.
Knoevenagel type condensation of 4-unsubstituted isoxazolinones with ketones or aldehydes followed by Michael addition of a nucleophile — hydride, cyanide, or phosphite— and exposure of the adduct to sodium nitrite/aqueous acetic acid and ferrous sulfate gives variously functionalised alkynes.
An unprecedented silver‐catalyzed difunctionalization of the isocyanogroup with cyclicoximes is described. This method allows efficient and atom‐economic assembly of a vast array of structurally novel and interesting pyrimidinediones, and tolerates a range of functionalities. The resulting products can be easily converted into some useful compounds. Furthermore, the method can also be applied for
Enantioselective Synthesis of Functionalized Diazaspirocycles from 4‐Benzylideneisoxazol‐5(4<i>H</i>)‐one Derivatives and Isocyanoacetate Esters
作者:Pablo Martínez‐Pardo、Adrián Laviós、Amparo Sanz‐Marco、Carlos Vila、José R. Pedro、Gonzalo Blay
DOI:10.1002/adsc.202000611
日期:2020.9.8
spirocyclic compounds bearing three contiguous stereocenters and high functionalization were obtained through a formal [3+2] cycloaddition reaction catalyzed by a cooperative system. The spiro compounds were synthesized from 4‐arylideneisoxazol‐5‐ones and isocyanoacetate esters using a bifunctional squaramide/Brønsted base organocatalyst derived from a Cinchona alkaloid and silver oxide as Lewis acid. This method
Difunctionalization of the Isocyano Group: Atom-Economic Synthesis of Pyrimidinediones
作者:Jian Lang、Ye Wei
DOI:10.1055/s-0037-1610348
日期:2019.2
the nitrogen and carbons atoms of the isocyanogroup would largely enrich the structural diversity of compounds. Herein, we disclosed a silver-catalyzeddifunctionalization of the isocyanogroup with cyclicoximes. This method can generate a great array of structurally novel and interesting pyrimidinediones and features excellent atom economy, good functional group compatibility, and amenability to late-stage