1361387-12-3

Relevant academic research and scientific papers

Fe(II)-Catalyzed Isomerization of 4-Vinylisoxazoles into Pyrroles

The first synthesis of pyrroles by Fe(II)-catalyzed isomerization of 4-vinylisoxazoles is reported. 5-Alkoxy, amino, and N,N-dialkylamino-3-aryl/alkyl-4-(2-R-vinyl)isoxazoles afford 2-aryl/alkyl-5-aryl/alkyl/methoxycarbonyl-1H-pyrrol-3-carboxylic acid derivatives typically under mild conditions with cheap and available FeCl2·4H2O as a catalyst. The isomerization of 5-alkoxy/amino-3-arylisoxazoles, bearing unsaturated carbo and heterocyclic substituents at the position 4, gives the corresponding fused pyrrolecarboxylic acid derivatives in high yields. DFT calculations were used to elucidate a probable mechanism of the isomerization and explain the influence of steric congestion of the vinyl moiety on the isomerization pathway.

A catalyst-controlled selective synthesis of pyridines and pyrroles

We have developed a dual reaction manifold that enables the selective synthesis of both pyridines and pyrroles from the common substrates α-diazo oxime ethers. The strong propensity of 1,3-dienyl nitrenes for 4π-electrocyclization to give pyrroles could be diverted to 6π-electrocyclization via a 1,6-hydride shift or prototropic isomerization, leading to the exclusive formation of pyridines by employing metal nitrene complexes derived from α-diazo oxime ethers under Rh(ii) catalysis. Furthermore, an orthogonal catalytic system has been identified that promotes the selective formation of 1H-pyrroles from the same substrates by redirecting the reactivity of vinyl 2H-azirine intermediates. This journal is the Partner Organisations 2014.

METHOD FOR PREPARING 2H-AZIRINE CARBOXYLIC ESTERS

The invention relates to a method for preparing 2H-azirine carboxylic esters. More specifically, the invention relates to a method for preparing 2H-azirine carboxylic esters starting from α-diazo-β-keto oxime ethers in the presence of a rhodium (II)-based