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Tomilov, Yu. V.; Kostyuchenko, I. V.; Shulishov, E. V.; Okonnishnikova, G. P.

doi:10.1023/a:1024429232345

Cited by 9 publications

(9 citation statements)

References 5 publications

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“…3 The cyclopropyldiazonium salt was prepared from N cyclo propyl N nitrosourea as described earlier. 10,11 Dimethyl 3 methoxycarbonyl 2 (triphenylphosphoranyl idene) 4,5 diazahept 5 ene 1,7 dioate (7b). A mixture of me thyl triphenylphosphoranylideneacetate (3b) (12.5 g, 37.4 mmol) and methyl diazoacetate (1.96 g, 19.6 mmol) in chloroform (25 mL) was kept at 20 °C for 12-14 days until the starting ylide was consumed ( 1 H NMR data).…”

Section: Resultsmentioning

confidence: 99%

Cascade reactions of nitrogen-and phosphorus-containing ylides with methyl diazoacetate and in situ generated diazocyclopropane

et al. 2006

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Reactions of pyridinium or phosphorus ylides with diazo esters are multistep processes. The first step is covalent bonding between the ylide C atom and the terminal N atom. This is followed by elimination of the ylide forming molecule and successive addition of one or two ylide fragments. Depending on the nature of the starting reagents, this type of transformations leads to novel polyfunctional phosphorus ylides or, with pyridinium ylides, to polyalkyl 3,4(4,5) diazaalkadienetri or tetracarboxylates. A reaction of the in situ generated diazocyclopropane with methyl triphenylphosphoranylideneacetate stops at the first step, giving a cyclopropylazo containing ylide. Reactions of the latter with acyl chlorides yield six membered heterocyclic betaines with a triphenylphosphonium substituent.Earlier, 1 we have found that carbene decomposition of methyl diazoacetate in boiling pyridine unexpectedly yields tetramethyl tetrahydropyridazine 3,4,5,6 tetra carboxylate (1) as a mixture of two geometrical isomers. Under more drastic conditions (boiling xylene in the pres ence of pyridine), tetramethyl pyrroletetracarboxylate (2) has been isolated as the major reaction product. Presum ably, these heterocyclic compounds can form via genera tion of intermediate pyridinium ylides followed by their reactions with a diazo compound. 1 To verify this assump tion, we have studied 2 reactions of alkyl diazoacetates with pyridinium ylides generated from other precursors (e.g., quaternary pyridinium salts prepared from haloacetic acid esters proved to be convenient precursors of such ylides 3 ).In fact, reactions of alkyl diazoacetates with pyridinium methoxycarbonylmethylide (3a) generated by decompo sition of a pyridinium salt with K 2 CO 3 ultimately af forded the same heterocycles 1 or 2 in 40-70% yields (Scheme 1). 2 The reaction rate and pathway depend on both the polarity of the medium and the temperature. This allowed us to isolate two novel acyclic intermediates 4 and 5 that are precursors of compounds 1 and 2. Rear rangement of azine 4 into diazadiene 5 followed by cy clization of the latter into tetrahydropyridazine 1 are ac celerated by bases or polar solvents.Using the starting compounds with different ester groups, e.g., (methoxycarbonyl)methylpyridinium iodide and ethyl diazoacetate, we found, from the numbers of the COOMe and COOEt groups in reaction products, that the formation of diazadienes 4 and 5 involves three ylide molecules and only one diazo ester molecule. 2 These results motivated us to study in more detail reactions of diazo compounds with ylides. Results and DiscussionPreviously, 2 we have determined only the final steps of multistep reactions of diazoacetate with ylides that first give rise to open structures 4 and 5 and then to hetero cyclic tetraesters 1 or 2. Here we tried to elucidate the character of cascade transformations during reactions of diazo compounds with ylides. In the hope of isolating products characteristic of the earlier steps of this process, we varied the nature (and, accordingly, react...

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Section: Resultsmentioning

confidence: 99%

Cascade reactions of nitrogen-and phosphorus-containing ylides with methyl diazoacetate and in situ generated diazocyclopropane

et al. 2006

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“…On account of this, we at first expected that these compounds, as well as the non-fluorinated β-diketones 5, [17] would show properties of active CH-acids and would undergo azo coupling with the cyclopropyldiazonium ion (2). The behaviour of the fluorine-containing diketones 10a,bϪ13a,b (Scheme 2), however, proved to differ clearly from that of their non-fluorinated analogues.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…[17] It is interesting to note analogously with diazocyclopropane (3) generated in situ, giving stable 2-(difluoromethyl) that under the same conditions cyclopropyldiazonium 2 and diazocyclopropane 3 or both can be intermediates in reactions with appropriate substrates, such as 4 and 5, to afford the products of 1,3-dipolar cycloaddition 6 in the case of unsaturated compounds [19] and the azo coupling products 7 in the case of CϪH acids. [17] It is also known [20Ϫ23] that diazocyclopropane generated in situ reacts with some ketones to form oxaspiropentane derivatives or the products of their rearrangement. Treatment of 3 with acetone 8 thus gave dimethyloxaspiropentane 9 (Scheme 1), [20] while reactions between 3 and the carbonyl groups of trispirodecanone [21] and of steroids [22,23] afforded the corresponding oxaspiropentanes, which rearranged to cyclobutanone derivatives under the reaction conditions used.…”

Section: Introductionmentioning

confidence: 99%

“…[11Ϫ14] We have recently reported that azo coupling products were obtained by decomposition of N-cyclopropyl-N-nitrosourea (1) with K 2 CO 3 in the presence of hydroxynaphthalenes, [15,16] hydroxyquinoline, [15] methyl cyanoacetate, [17] malonodinitrile, [17] pyrazoline derivatives [18] and some β-diketones. [17] It is interesting to note analogously with diazocyclopropane (3) generated in situ, giving stable 2-(difluoromethyl) that under the same conditions cyclopropyldiazonium 2 and diazocyclopropane 3 or both can be intermediates in reactions with appropriate substrates, such as 4 and 5, to afford the products of 1,3-dipolar cycloaddition 6 in the case of unsaturated compounds [19] and the azo coupling products 7 in the case of CϪH acids.…”

Section: Introductionmentioning

confidence: 99%

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Fluorinated β‐Diketones in Reactions with Diazocyclopropane Generated in situ

et al. 2004

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Treatment of 1,1‐di‐ and 1,1,1‐trifluoroalkane‐2,4‐diones 10−13 with cyclopropyldiazonium intermediates 2 and 3, generated in situ through the decomposition of N‐cyclopropyl‐N‐nitrosourea 1 by treatment with moist K2CO3, did not result in the expected azo coupling of the cyclopropyldiazonium ion, but afforded the corresponding oxaspiropentanes 14−17 as products of the addition of diazocyclopropane (3) onto one of the carbonyl groups. In addition, the reaction proceeded selectively on the carbonyl groups adjacent to the di‐ or trifluoromethyl substituents. 1,1‐Difluoroacetone reacted analogously with diazocyclopropane (3) generated in situ, giving stable 2‐(difluoromethyl)‐2‐methyloxaspiropentane in approximately 50% yield. The resulting oxaspiropentanes 14−17, on heating or in the presence of lithium iodide, rearranged selectively into cyclobutanones 20−23, while in the presence of Al2O3 they formed mixtures of approximately equal amounts of the corresponding cyclobutanones and the 1‐vinylcyclopropanols 24−27. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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Formation of N‐Cyclopropylhydrazones by Azo Coupling of Cyclopropyldiazonium with Aliphatic CH Acids.

et al. 2003

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Cyclopropane derivativesCyclopropane derivatives Q 0021 Formation of N-Cyclopropylhydrazones by Azo Coupling of Cyclopropyldiazonium with Aliphatic CH Acids. -Decomposition of N-cyclopropyl-N-nitrosourea (I) under alkaline conditions results in the formation of cyclopropyldiazonium salts, which smoothly react with CH-acids to form the corresponding cyclopropylhydrazones [cf. (III), (V)/(VI)]. -(TOMILOV*, Y. V.; KOSTYUCHENKO, I. V.; SHULISHOV, E. V.; OKONNISHNIKOVA, G. P.; Russ.

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Cited by 9 publications

References 5 publications

Cascade reactions of nitrogen-and phosphorus-containing ylides with methyl diazoacetate and in situ generated diazocyclopropane

Cascade reactions of nitrogen-and phosphorus-containing ylides with methyl diazoacetate and in situ generated diazocyclopropane

Fluorinated β‐Diketones in Reactions with Diazocyclopropane Generated in situ

Formation of N‐Cyclopropylhydrazones by Azo Coupling of Cyclopropyldiazonium with Aliphatic CH Acids.

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