Dihydro-1,3-diazepinones and diazabicyclo[3.2.0]heptenones from pyridyl azides

Reisinger, Ales; Koch, Rainer; Wentrup, Curt

doi:10.1039/a804831b

Cited by 26 publications

(11 citation statements)

References 2 publications

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“…Synthesis of 2-methoxy or 2-amino 1,3-diazepines through the reaction of cyclic carbodiimides. [51] In 2011, Ryan et al reported a new way to access 1,3benzodiazepin-5-one derivatives 166 from isatoic anhydrides 161 (Scheme 39). [60] The transformation involved a 1,3-dipolar cycloaddition reaction of a nonstabilized azomethine ylide with a wide range of isatoic anhydrides to give oxazolidine intermediates 162.…”

Section: Six-member Heterocyclic Ring Transformationmentioning

confidence: 99%

1,3‐Diazepine Derivatives: Strategies for Synthesis

2021

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Section: Six-member Heterocyclic Ring Transformationmentioning

confidence: 99%

1,3‐Diazepine Derivatives: Strategies for Synthesis

2021

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“…2-Dialkylamino-1H-1,3-diazepines 141a and 2-alkoxy-1H-1,3-diazepines 141b are obtained by the preparativescale photolysis of substituted 2-azidopyridines 138 (Scheme 12.37). The irradiations were generally performed in dioxane, and in the presence of nucleophiles such as [91,92]. The reaction can be considered quite general and efficient, and is explained through the pyridylnitrene 139 and the cyclic carbodiimide 140.…”

Section: Diazepinesmentioning

confidence: 99%

“…The reaction can be considered quite general and efficient, and is explained through the pyridylnitrene 139 and the cyclic carbodiimide 140. In the case of the alkoxy compounds, the 1-H form is generally predominant; this differs in the case of the dialkylamino compounds, where the 5-H form is favored [92]. Variously substituted 2-azido-pyridines have been irradiated on a preparative scale in the presence of alcohols or amines for the synthesis of the corresponding variously substituted 1,3-diazepines, in good to high yields.…”

Section: Diazepinesmentioning

confidence: 99%

Synthesis of Heteroaromatics via Rearrangement Reactions

Vivona

Buscemi

Pibiri

et al. 2009

Handbook of Synthetic Photochemistry

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The varied family of heteroaromatics contains a large fraction of organic compounds, many of which have found important applications in different fields. Many synthetic methodologies have been developed to obtain target systems and, among them, photochemical methods represent valid and elegant alternatives when the final targets are difficult to obtain through ground-state chemistry. In this chapter, we describe the photochemical synthesis of heteroaromatic compounds through rearrangement reactions, particularly via ring-transformations of heterocyclic precursors [1][2][3][4][5][6][7].A classification of all photoinduced heterocyclic ring-transformation reactions is quite difficult to achieve due to the large variety of mechanistic pathways, experimental conditions and affecting parameters. In some cases, the photochemical product and the starting substrate have the same heterocyclic nucleus. In this chapter, we will refer to such reactions, characterized by the identity of the starting and final ring, as ring-degenerate rearrangements.In general, photoinduced rearrangements of heterocycles leading to heteroaromatic compounds may involve ring-contraction, internal cyclization, ring-expansion, ring-opening or ring-closure, and ring-fragmentation processes. As for five-membered rings, two processes will be repeatedly quoted throughout this chapter:. The ring contraction-ring expansion route (RCRE), which explains the formal interchange between two adjacent ring-atoms. This results from the photoinduced cleavage of the weakest bond in the ring with formation of a three-membered ring intermediate. The latter is then converted, either thermally or photochemically, into the final five-membered heterocyclic product (see e.g., Scheme 12.22). . The internal cyclization-isomerization route (ICI), which involves the formation of a bicyclic species featuring a single bond between the ring-atoms in the 2-and 5-positions of the original heterocycle. Sigmatropic shifts then occur, leading to different bicyclic intermediates from which the final products will arise (see e.g., Scheme 12.2).Handbook of Synthetic Photochemistry. Edited

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“…Smaller amounts of glutacononitrile (by ring opening), and 2-aminopyridine (by H-abstraction, probably from the triplet nitrene) are also formed. [59,60,73,74] The ring expansions (to 7-membered ring carbodiimides) and ring contractions (to 5-membered ring nitriles) and/or ring opening of several aza and benzo derivatives have been described. [59,60,66] Scheme 15…”

Section: Carbodiimides From Tetrazolesmentioning

confidence: 99%