18441-60-6Relevant academic research and scientific papers
NOVEL METHODS FOR PREPARATION OF SUBSTITUTED PYRIDINES AND RELATED NOVEL COMPOUNDS
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Paragraph 0195; 0196; 0197; 0264; 0265, (2020/04/10)
The present invention relates to novel methods of preparation of substituted pyridines and the compounds produced therefrom. In particular, the present invention provides efficient methods for the construction of diversely substituted pyridines, with varying substitution patterns under simple and metal-free conditions with high atom- and pot-economy and excellent functional group tolerance, and which are useful for the synthesis of natural products.
A simple, tandem approach to the construction of pyridine derivatives under metal-free conditions: A one-step synthesis of the monoterpene natural product, (-)-actinidine
Uredi, Dilipkumar,Motati, Damoder Reddy,Blake Watkins
supporting information, p. 3270 - 3273 (2019/03/30)
A simple and modular one-step synthesis of diversely substituted pyridines from readily available α,β-unsaturated carbonyl compounds and propargylic amines has been developed. The present protocol has a broad substrate scope and allows access to multi-substituted pyridines with select control of the substitution pattern under mild and metal-free conditions. The reaction involves imine formation followed by concomitant cyclization through an allenyl intermediate to afford pyridines in excellent yields, with water as the sole by-product. This mild strategy is also suitable for functionalization of natural products or other advanced intermediates having α,β-unsaturated carbonyl functionality. The utility of the present protocol was showcased with the synthesis of the monoterpene alkaloid, (-)-actinidine, an ant-associated iridoid.
Synthesis of dihydropyridines and pyridines from imines and alkynes via C-H activation
Colby, Denise A.,Bergman, Robert G.,Ellman, Jonathan A.
, p. 3645 - 3651 (2008/10/09)
A convenient one-pot C-H alkenylation/electrocyclization/aromatization sequence has been developed for the synthesis of highly substituted pyridine derivatives from alkynes and α,β-unsaturated N-benzyl aldimines and ketimines that proceeds through dihydropyridine intermediates. A new class of ligands for C-H activation was developed, providing broader scope for the alkenylation step than could be achieved with previously reported ligands. Substantial information was obtained about the mechanism of the reaction. This included the isolation of a C-H activated complex and its structure determination by X-ray analysis; in addition, kinetic simulations using the Copasi software were employed to determine rate constants for this transformation, implicating facile C-H oxidative addition and slow reductive elimination steps.
