5,6-Dihydropyridin-2(1H)-ones and 5,6-dihydropyridine-2(1H)-thiones (review)

Fisyuk, A. S.; Bundel, Yu. G.

doi:10.1007/bf02251699

Cited by 18 publications

(11 citation statements)

References 85 publications

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“…Exposure of 1,4-oxazines to the mild basic conditions gave pharmacologically important hexahydroquinoline-2(1H)-ones 114-115 in good yields. [20] This unusual transformation proceeds through base-mediated ring rear-rangement, Grob-type fragmentation, [21] and oxidation. In the presence of a non-nucleophilic base or acid, the hemiketal moiety of 1,4-oxazine triggers ring-opening rearrangement resulting in hexahydroquinolines 116-122 in moderate to good yields (see SI for mechanism).…”

Section: [B]mentioning

confidence: 99%

Rh‐Catalyzed Chemodivergent [3+3] Annulations of Diazoenals and α‐Aminoketones: Direct Synthesis of Functionalized 1,2‐Dihydropyridines and Fused 1,4‐Oxazines

Mandal,

Katukojvala

2024

Chemistry A European J

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Novel rhodium‐catalyzed [3+3] annulations of diazoenals and α‐amino ketones has been disclosed here. The reactivity of diazoenals has been switched from carbenoid to vinylogous NH‐insertion by altering acyclic to cyclic α‐aminoketones. In this direction, we report an efficient strategy to synthesize 1,2‐dihydropyridines (DHPs) and fused 1,4‐oxazines. Mechanistic investigation revealed that the formyl group is necessary for carbenoid [3+3] annulation and the cyclohexyl group is the dictating factor for vinylogous NH‐ insertion. The synthetic utility of 1,2‐dihydropyridines was demonstrated by synthesizing piperidine, pyrido[1,2‐a]indole, and 2‐pyridone scaffolds..Further, structural diversification of fused 1,4‐oxazines resulted in the short synthesis of hexahydroquinolin‐2(1H)‐ones, hexahydro quinolines and tetrahydroquinolinones via ring opening rearrangement and a new oxidative deformylation, respectively.

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Section: [B]mentioning

confidence: 99%

Rh‐Catalyzed Chemodivergent [3+3] Annulations of Diazoenals and α‐Aminoketones: Direct Synthesis of Functionalized 1,2‐Dihydropyridines and Fused 1,4‐Oxazines

Mandal,

Katukojvala

2024

Chemistry A European J

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“…The tetracyclic compounds 314 with a linear condensed structure containing a pyridine ring were synthesized with yields of 58% (R`= H) and 82% (R`= Cl) by the condensation of the anhydride 312 namely, 2H-3,1-benzoxazin-2,4- 5,6-Dihydropyridin-2(1H)-ones possess significant importance due to both their biological activity [183] and their utilization in the synthesis of more complex compounds [184]. The main method for their synthesis is dehydrogenation of -valerolactam (2-piperidone), but this route is limited by the availability of the required starting materials [183,185].…”

Section: Pyridine Derivativesmentioning

confidence: 99%

Utilities of Some Carbon Nucleophiles in Heterocyclic Synthesis

Madkour¹,

Elgazwy

2007

COC

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New developments in the utilities of some carbon nucleophiles in heterocyclic synthesis are reviewed. General synthetic routes based on the utilization of carbon nucleophiles of active methylene are discussed. The major methods and modifications are analyzed. Heterocycles are ubiquitous in all kind of compounds of interest, and among all the possible synthetic methods of achieving their introduction into a structure, probably the use of a carbon nucleophile analogues are the most direct one. The present review deals with the generation and synthetic of carbon nucleophile, which uses as scaffold for the heterocyclic synthesis, and can be considered as an update review. Therefore the only references published upon the second quarter of 2003 are included, and the same restrictions to the literature coverage apply.

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“…5,6-Dihydropyridin-2(1H)-ones possess significant importance due to both their biological activity [ 1 ] and their utilization in the synthesis of more complex compounds [ 2 ]. The main method for their synthesis is dehydrogenation of δ-valerolactams, but this route is limited by the availability of the required starting materials [ 1 , 3 ]. Although the Wittig reaction is widely used for the synthesis of heterocycles [ 4 ], the cyclization of N-(3-oxoalkyl)amides derivatives using this reaction has not been investigated until now.…”

Section: Introductionmentioning

confidence: 99%