Diazocarbonyl Compounds Research Articles

Chemistry of Diazocarbonyl Compounds. Part 30. Development of a Synthetic Approach to Pyridazine Structure via Wittig Reaction of Fluoroalkyl‐Containing Diazo Keto Esters.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Copper‐Promoted Cycloaddition of Diazocarbonyl Compounds and Acetylides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Insertion reactions of macrocyclic rhodium carbenoids: a novel method for the synthesis of cryptands

Reaction of macrocyclic diazocarbonyl compounds and alcohols or diols in the presence of rhodium(II) acetate catalyst led to functionalized macrocyclic di- or tetralactones via O–H insertion. Interestingly, the double O–H insertion reaction with dihydroxy compounds gave cryptands of various ring sizes.

3+2] Cycloaddition of Diazocarbonyl Compounds to 1,1-Dinitroethenes: Synthesis of Functionalized gem-Dinitrocyclopropanes

The synthesis of functionalized gem-dinitrocyclopropanes via [3+2] cycloaddition of diazocarbonyl compounds with 1,1-dinitroethenes [in some cases in the presence of Mo(CO)6 as catalyst] has been developed.

Rh-catalyzed transannulation of pyridotriazoles with alkynes and nitriles.

Rh-catalyzed transannulation of pyridotriazoles with alkynes and nitriles.

Chemistry of Diazocarbonyl Compounds. Part 28. Reaction of Acyclic N‐Arylsulfonylacetamides with Rh(II)‐Carbenoids as a New Synthetic Route to Alkyl Acetimidoates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Copper-Promoted Cycloaddition of Diazocarbonyl Compounds and Acetylides

Copper-Promoted Cycloaddition of Diazocarbonyl Compounds and Acetylides

Copper‐Promoted Cycloaddition of Diazocarbonyl Compounds and Acetylides

HOMO-logous: The copper-mediated cycloaddition of alkynes with diazo carbonyl compounds to give pyrazoles is reminiscent of the copper-catalyzed cycloaddition of alkynes and azides. The formation of the copper acetylide is proposed to narrow the energy gap between the highest occupied molecular orbital (HOMO) of the alkyne and the lowest unoccupied molecular orbital (LUMO) of the diazo compound.

Chemistry of diazocarbonyl compounds: XXX. Development of a synthetic approach to pyridazine structure via wittig reaction of fluoroalkyl-containing diazo keto esters

3,4,6-Trisubstituted pyridazines were synthesized from fluoroalkyl-containing diazo keto esters in three steps along two different reaction sequences: (1) Wittig, Staudinger, and diaza-Wittig and (2) Staudinger, Wittig, and diaza-Wittig. According to the first of these with the initial Wittig reaction, the yield of the target 4-fluoroalkyl-substituted pyridazines is almost twice as large as in the reaction sequence involving the corresponding N-phosphanylidene derivatives as intermediates. In both sequences, the final steps (synthesis of vinylphosphazenes and the subsequent diaza-Wittig reaction) occurred as a tandem process, and intermediate vinylphosphazenes could not be isolated. Non-fluorinated diazo keto esters and the respective phosphazenes failed to react with alkoxycarbonylmethylidene(triphenyl)phosphoranes under the same conditions.

Palladium‐mediated copolymerization of diazocarbonyl compounds with phenyldiazomethane

AbstractPhenyldiazomethane was found to be polymerized by the reaction with palladium‐based initiating systems. Homopolymerization of phenyldiazomethane afforded a polymer, whose main chain consists of phenylmethylene framework (–CHPh–) and azo groups (–NN–). The incorporation of the azo group was suggested from the results of elemental analyses, and confirmed by Raman spectroscopy. Palladium‐mediated copolymerization of phenyldiazomethane with (E)‐1‐diazo‐3‐nonen‐2‐one or ethyl diazoacetate proceeded to give copolymers having phenylmethylene framework, azo group, and acylmethylene or ethoxycarbonylmethylene framework in the main chain, with a variety of their compositions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1536–1545, 2007

Spirocyclic and Fused Derivatives of Maleimide Based on Intra- and Intermolecular Reactions of Carbonyl Ylides from Diazocarbonyl Compounds

The reaction of maleimide with Rh(II)-ketocarbenoids, derived from acyclic diazocarbonyl compounds, proceeds chemoselectively at the oxygen atom of the imidic C=O group to give carbonyl ylides as reactive intermediates. The carbonyl ylide generated from maleimide and ethyl diazoacetate reacts intermolecularly with the double bond of another molecule of maleimide to yield tricyclic spiroadducts via [3+2]-cycloaddition. Intramolecular stabilization is characteristic for carbonyl ylides with two bulky electron-withdrawing groups at the carbanionic center and occurs in two different ways, depending on the structure of the substituents: carbonyl ylides from diazomalonate, which possess two alkoxycarbonyl groups at the carbanionic C-atom, experience a 1,3-dipolar electrocyclization with formation of an oxirane, while carbonyl ylides with at least one α-acyl group, derived from diazoacetoacetate or diazoacetylacetone, undergo an intramolecular 1,5-dipolar electrocyclization to produce 1,3-dioxole derivatives of maleimide.

Chemistry of Diazocarbonyl Compounds. Part 27. Thermolysis and Photolysis of Diazirines, Derivatives of 1,3‐Dioxane‐4,6‐dione.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Chemistry of diazocarbonyl compounds: XXVIII. Reaction of acyclic N-arylsulfonylacetamides with Rh(II)-carbenoids as a new synthetic route to alkyl acetimidoates

A new procedure was proposed for the synthesis of alkyl acetimidoates via alkylation of the carbonyl group in N-arylsulfonylacetamides with Rh(II)-carbenoids. The procedure ensures preparation in good yield of acetimidoates having a polyfunctionalized O-alkyl group. The obtained alkyl acetimidoates in crystal exist as E isomers with respect to the C=N bond and as s-cis conformers relative to the C-OCHRR’ bond. Alkyl N-arylsulfonylacetimidoates react with ammonia and hydrazine hydrate to give in good yield the corresponding carboximidamides(hydrazides) via replacement of the O-alkyl group. Unlike structurally related compounds having simple alkyl or aryl groups on the nitrogen atom, N-arylsulfonylacetimidoates readily undergo hydrolysis in the presence of moisture and traces of acids.

Rhodium(II)-Catalyzed Reaction of Diazocompounds in the Service of Organic Synthesis of Natural and Non-Natural Products

The rhodium(II)-carbenoid mediated transformation of diazocarbonyl compounds is well recognized as a useful process for the facile formation of carbon-carbon and carbon-heteroatom bonds under mild reaction conditions. In this review, the incorporation of rhodium(II)-carbenoid transformations in the synthetic planning and the eventual application of rhodium(II) carbenoid reactions in the synthesis of natural products, non-natural compounds of medicinal importance, and advanced intermediates are discussed. Focus is placed on the use of intermolecular and intramolecular C-H and X-H insertion, intermolecular and intramolecular cyclopropanation, and tandem ylide (carbonyl, ammonium, oxonium, sulfonium) formation/1,3-dipolar cycloaddition, [2,3]-sigmatropic or Stevens [1,2]-rearrangement reactions as key step(s) in the synthetic routes. Keywords: Rhodium-carbenoid, insertion, cyclopropanation, ylide, enantioselective, diastereoselective, synthesis, metallocarbene

Chemistry of Diazocarbonyl Compounds. Part 25. Comparative Photochemistry of Diazo Compounds and Sulfur Ylides of the 1,3‐Dioxane‐4,6‐dione Series.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

RhII‐Catalyzed Reactions of Diazocarbonyl Compounds with Dicarboximides

AbstractThe reaction of RhII–oxocarbenoids derived from acyclic diazocarbonyl compounds with phthalimide and succinimide proceeds chemoselectively at the oxygen atom of the imidic carbonyl group, giving rise to the intermediate formation of carbonyl ylides. Intramolecular stabilization of these highly reactive species occurs in three different ways, and is controlled by the structure of the 2‐oxocarbenoids. Carbonyl ylides from diazo esters mainly experience a [1,4]‐hydrogen shift, and in this case, the corresponding O‐alkylimidates are formed as the final products. These ylides may also be stabilized by 1,3‐dipolar electrocyclization with intermediate formation of an oxirane. Carbonyl ylides with an acyl group in the carbene moiety undergo an intramolecular 1,5‐dipolar electrocyclization to produce 1,3‐dioxole derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Transition Metal-Mediated Copolymerization of Diazocarbonyl Compounds with Alkyne and Isocyanide

Transition metal-mediated copolymerizations of diazocarbonyl compounds with alkynes and an isocyanide were investigated with the following combinations of the comonomers: (E)-1-diazo-3-nonen-2-one (1a) with phenylacetylene (2a), (E)-1-diazo-4-phenyl-3-buten-2-one (1b) with 1-heptyne (2b), ethyl diazoacetate (1c) with 2a and 2b, and 1b with tert-butyl isocyanide (3). All the copolymerizations afforded random copolymers whose GPC traces were unimodal, and 1H NMR spectra exhibited superposition of signals derived from the repeating units of both comonomers. In addition, the progress of the copolymerizations was supported by the DSC analyses of the products.

Chemistry of diazocarbonyl compounds: XXVII. Thermolysis and photolysis of diazirines, derivatives of 1,3-dioxane-4,6-dione

Photolysis of diazirines, 1,3-dioxane-4,6-dione derivatives, occurs in the presence of methanol or dimethyl sulfide as carbene traps without a formation of carbene intermediates. It was established for the first time that the thermolysis and photolysis of diazirines from the 1,3-dioxane-4,6-dione series led mainly to Wolff rearrangement with a subsequent formation of 5-oxo-1,3-dioxolane-4-carboxylic acids or their derivatives. The data obtained show that the α-oxodiazirines are the key intermediates in the photolysis and Wolff rearrangement of α-diazocarbonyl compounds.

1,2-Migration in Rhodium(II) Carbene Transfer Reaction: Remarkable Steric Effect on Migratory Aptitude

A series of diazo carbonyl compounds bearing different substituents have been prepared in order to investigate the steric effect in 1,2-migration reaction of rhodium(II) carbene. Through the investigation on the diazo decomposition of these compounds with Rh2(OAc)4, it was found that the steric effect could dramatically influence the migratory aptitude. In many cases, the steric effect could override the inherent electronic effect of the substituent.

Chemistry of diazocarbonyl compounds: XXV. Comparative photochemistry of diazo compounds and sulfur ylides of the 1,3-dioxane-4,6-dione series

Photochemical decomposition of 2,2-dialkyl-5-diazo-1,3-dioxane-4,6-diones in the presence of pyridine, methanol, or dimethyl sulfide as carbene traps involves mainly the Wolff rearrangement which is likely to follow a concerted pattern, while the yield of the “carbene” products does not exceed 27–28%. No carbene intermediates are formed in the photolysis of the corresponding dioxo sulfonium ylides under analogous conditions, and the main photochemical process is 1,2-methyl shift (Stevens rearrangement), followed by photochemical transformations of the primary products according to the Norrish type II pattern.