27068-69-5Relevant articles and documents
Chiral 1,2-dihydropyridine compound as well as preparation method and application thereof
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Paragraph 0194-0196, (2020/01/03)
The invention discloses a synthesis method for preparing chiral polysubstituted 1,2-dihydropyridine as well as polysubstituted pyridine and chiral piperidine derived from chiral polysubstituted 1,2-dihydropyridine by using a "one-pot serial connection method". The method comprises the following step: by taking an imine compound and an aldehyde compound as raw materials, performing an asymmetric Mannich reaction, a Wittig reaction and an intramolecular ring-closing reaction in sequence, so as to synthesize a chiral 1,2-dihydropyridine compound with high three-dimensional selectivity. The product does not need to be purified, and a polysubstituted pyridine compound can be prepared through oxidation aromatization through further "one-pot serial connection", and a polysubstituted chiral piperidine compound can be also prepared through catalytic hydrogenation after separation and purification. The method starts from simple and easily obtained raw materials, separation and purification of anintermediate are avoided, and compounds of 1,2-dihydropyridine, polysubstituted pyridine and chiral piperidine are efficiently synthesized through simples steps of operation. Nitrogenous six-memberedring frameworks which are synthesized by using the method and disclosed by the invention are all common in many natural products and medicine molecules, and have great significances for acceleratingmedicine research and development.
Regioselective Pd-Catalyzed Synthesis of 2,3,6-Trisubstituted Pyridines from Isoxazolinones
Rieckhoff, Stefan,Hellmuth, Tina,Peters, René
, p. 6822 - 6830 (2015/10/05)
Substituted pyridines are prevalent heterocycles of fundamental importance. Their efficient regioselective preparation is often still a challenge despite a large number of reported synthetic methodologies. In this letter we report an operationally simple approach that makes use of readily accessible isoxazolinones. The protocol involves a Pd(II)-catalyzed C-regioselective 1,4-addition to vinylketones, followed by a Pd(0)-catalyzed transformation, which is assumed to proceed via vinylnitrene-Pd intermediates. Both hydrogen and air are necessary for the pyridine formation step and could be employed at ratios above the upper explosive limit thus avoiding a safety issue. This new strategy allows an effective, scalable and practical access to various previously unknown 2,3,6-trisubstituted pyridines.
Heteroaromatic synthesis via olefin cross-metathesis: Entry to polysubstituted pyridines
Donohoe, Timothy J.,Basutto, Jose A.,Bower, John F.,Rathi, Akshat
, p. 1036 - 1039 (2011/04/27)
The olefin cross-metathesis reaction provides a rapid and efficient method for the synthesis of α,β-unsaturated 1,5-dicarbonyl derivatives which then serve as effective precursors to mono-tetrasubstituted pyridines. Manipulation of the key 1,5-dicarbonyl intermediate allows access to pyridines with a wide range of substitution patterns. An extension of this methodology facilitates the preparation of pyridines embedded within macrocycles, as exemplified by an efficient synthesis of (R)-(+)-muscopyridine. High levels of regiocontrol, short reaction sequences, and facile substituent variation are all notable aspects of this methodology.(Figure Presented)
