نتایج جستجو برای: pyridines
تعداد نتایج: 6741 فیلتر نتایج به سال:
The iron-catalyzed arylation of aromatic heterocycles, such as pyridines, thiophenes, and furans, has been achieved. The use of an imine directing group allowed for the ortho functionalization of these heterocycles with complete conversion in 15 min at 0 °C. Yields up to 88% were observed in the synthesis of 15 heterocyclic biaryls.
available and the reaction has the potential for the simultaneous creation of multiple stereocenters. Here we describe an efficient and unprecedented auxiliary-based method for the asymmetric hydrogenation of substituted pyridines (YR= N), which enables the stereoselective formation of piperidines with up to four new chiral centers in a single operation (Scheme 2a). The heterogeneous catalytic ...
Pyridines and diazines are critical structural elements in many biologically active small molecules and, as a result, signicant research effort has been devoted to their preparation. In addition to de novo heterocycle assembly, a number of powerful methods exist for the functionalization of these heteroarenes. For example, Minisci radical addition is a direct and effective synthetic approach t...
A new LiI-promoted O- to N-alkyl migration has been developed for the conversion of O-alkylated 2-hydroxy pyridines, quinolines, and pyrimidines to the corresponding N-alkylated heterocycles in good to excellent yields (57-99%). This method serves as an efficient means for the preparation of N-benzyl pyridones, quinolones, and pyrimidones.
The first total synthesis of pterocellin A (1) was achieved in 10 linear steps from commercially available kojic acid (6) and 2-bromo-3-pyridinol (11) in a convergent sequence. The key constructive steps are a directed lithiation to couple two pyridines and an intramolecular nucleophilic aromatic substitution to form 1. [structure: see text]
A copper-mediated three-component approach towards the synthesis of 3-cyanoimidazo[1,2-a]pyridines from 2-aminopyridines, acetophenones and benzyl cyanide was developed. This cascade reaction proceeds through a copper-mediated oxidative release of cyanide from benzyl cyanide, a copper-mediated Ortoleva-King reaction, and a copper-catalyzed cyanation.
We report the Cu-promoted oxidative cross-coupling of αfluoromalonate half-esters and aryl boron reagents to deliver monofluoro α-aryl acetates under mild conditions (in air at room temperature). The reaction uses a simple, readily available monofluorinated building block to generate arylated compounds with functional groups that are not easily tolerated by existing methods, such as aryl bromid...
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