Conjugated nitrosoalkenes

Lyapkalo, Ilya M.; Ioffe, Sema L.

doi:10.1070/rc1998v067n06abeh000406

Cited by 78 publications

(40 citation statements)

References 152 publications

(251 reference statements)

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“…[10b] The latter are Michael acceptors and readily react with nucleophiles. [15] In the case of cyclic N-alkoxy,N-siloxyenamines 2 possessing two non-equivalent NÀOb onds thesep rocesses would lead to two different nucleophilic addition products (Scheme 1). Evidently,b oth pathways may be affectedb y am etal ion, which can bind to oxygen atoms of the NÀO bonds.…”

Section: Introductionmentioning

confidence: 99%

Divergent Reactivity of In Situ Generated Metal Azides: Reaction with N,N‐Bis(oxy)enamines as a Case Study

Zhmurov

Khoroshutina

Новиков

et al. 2017

Chemistry A European J

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What is the most significant result of this study? Non-alkali metal azides are explosive compounds, which can hardly be considered as convenient and useful reagents in organic synthesis. However,a sw ed iscovered in our study the metal ion can modulate the reactivity of the azide anion thus opening new opportunities for the synthesis of organic azides. The compromise is that the use of af ree-metal azide is not needed, since it can be safely generated in solution by ion exchange from NaN 3 and the corresponding metal salt. What was the inspiration for this cover design? The inspiration for the cover picture came from cue sports. We make an analogy of the chemical behavior observed in our studies with ab illiard game, in which balls are ions, and pockets are reac-tive centers of an organic molecule. Unlike in ar eal game based on mechanics, in a" chemical billiard", ion balls after collision may not only bounce off each other,b ut also can fuse to form ac ova-lently bonded pair,w hich moves along its own trajectory.A "metal-ion ball" depending on its nature, directs the attack of the "azide-anion ball" on either one or another electrophilic "pocket" of the substrate (silicon or carbon atoms). Thus, ac hemist is like ap rofessional billiard player selecting the right ball (promoter/cat-alyst) and disposition (reaction conditions) to hit the target center in the molecule. This simple allegory illustrates the results described in our article in ap opular and easy-to-understand manner. What other topics are you working on at the moment? Although we are originally synthetic chemists, our research interests go far beyond the borders of traditional synthesis. Besides our focus on NÀOs ystems and stereoselective synthesis, we are working in the areas of medicinal chemistry,c lick reactions, coordination compounds, polymers and quantum-chemical calculations. Our particular passions are adamantane-like molecules. Among our recent achievements are the synthesis and structural studies of "isourotropine" (the isomer of methenamine) and B,O,N-doped adamantanes. Invited for the cover of this issue is the group of Alexey Sukhorukov at the N. D. ZelinskyI nstitute of Organic Chemistry. The image depicts the reaction pathways taken by metal azides as a" chemical billiard"g ame. Read the full text of the arti

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Section: Introductionmentioning

confidence: 99%

Divergent Reactivity of In Situ Generated Metal Azides: Reaction with N,N‐Bis(oxy)enamines as a Case Study

Zhmurov

Khoroshutina

Новиков

et al. 2017

Chemistry A European J

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“…a-Nitrosoalkenes constitute an exceptional class of highly reactive heterodienes, and their Diels-Alder reactions with C=C and CC dienophiles have been studied by experiments [19] and with computational methods. [20] Confirming an early study on a-nitrosoalkene/thioketone cycloadditions, [21] we recently described regioselective hetero-Diels-Alder reactions of aryl-, hetaryl-, and ferrocenyl-substituted thioketones with in situ generated electron-deficient a-nitrosoalkenes 10.…”

Section: Introductionmentioning

confidence: 99%

The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies

Mlostoń

Urbaniak

Jasiński

et al. 2019

Chemistry A European J

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The [4+2]‐cycloadditions of α‐nitrosoalkenes with thiochalcones occur with high selectivity at the thioketone moiety of the dienophile providing styryl‐substituted 4H‐1,5,2‐oxathiazines in moderate to good yields. Of the eight conceivable hetero‐Diels–Alder adducts only this isomer was observed, thus a prototype of a highly periselective and regioselective cycloaddition has been identified. Analysis of crude product mixtures revealed that the α‐nitrosoalkene also adds competitively to the thioketone moiety of the thiochalcone dimer affording bis‐heterocyclic [4+2]‐cycloadducts. The experiments are supported by high‐level DFT calculations that were also extended to related hetero‐Diels–Alder reactions of other nitroso compounds and thioketones. These calculations reveal that the title cycloadditions are kinetically controlled processes confirming the role of thioketones as superdienophiles. The computational study was also applied to the experimentally studied thiochalcone dimerization, and showed that the 1,2‐dithiin and 2H‐thiopyran isomers are in equilibrium with the monomer. Again, the DFT calculations indicate kinetic control of this process.

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“…These reactions are characterized by an asynchronous bond formation, a process initiated by the formation of the first a-bond between the most electrophilic and nucleophilic centers of the reagents with concomitant ring-closure. This is the case of the reaction of conjugated nitrosoalkenes, generated in situ by base-mediated dehydrobromination of a-bromooximes, with electron rich olefins which has been explored as a general route to oxazines, the expected Diels-Alder cycloadducts [1][2][3]. On the other hand, nitrosoalkenes 2a and 2b are known to react with electron rich heterocycles such as pyrrole and indole to give open chain oximes resulting from rearomatization of the pyrrole unit of the initially formed Diels-Alder cycloadducts.…”

Section: Introductionmentioning

confidence: 99%

Reactivity of 1-arylnitrosoethylenes towards indole derivatives

et al. 2016

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The reactivity of 1-arylnitrosoalkenes toward indole, 1-methylindole, and 3-methylindole is described. In contrast with the previously observed chemical behaviour of 1-(p-bromophenyl)nitrosoethylene towards pyrrole, the studied heterodienes reacted with indole and 1-methylindole to afford E-oximes via hetero-Diels-Alder reactions. The reaction with 3-methylindole also proceeds via cycloaddition giving the corresponding 1,2-oxazine. Quantum chemical calculations, at the DFT level, indicate that the energy barriers associated with the reactions between 1-(p-bromophenyl)nitrosoethylene and indole and its derivatives are similar to those observed for the reaction between this nitrosoalkene and pyrrole. However, the calculated energy of the theoretical Diels-Alder cycloadducts involving indole and pyrrole clearly suggests that the Diels-Alder reaction is privileged in the case of indole. Furthermore, in the case of the indole, the energy difference between reactants and products clearly favors the regiochemistry observed experimentally. Graphical abstract N H N H O N N H N HO Br Br

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Conjugated nitrosoalkenes

Cited by 78 publications

References 152 publications

Divergent Reactivity of In Situ Generated Metal Azides: Reaction with N,N‐Bis(oxy)enamines as a Case Study

Divergent Reactivity of In Situ Generated Metal Azides: Reaction with N,N‐Bis(oxy)enamines as a Case Study

The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies

Reactivity of 1-arylnitrosoethylenes towards indole derivatives

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