Diazocarbonyl Compounds Research Articles

One-Step Synthesis of Tertiary α-Amino Ketones and α-Amino Esters From Amines and Diazocarbonyl Compounds

Diazoketones and diazoesters react with tertiary amines in the presence of copper powder to form transient ammonium ylides. These ylides undergo facile [1,2]-shift from N to C (Stevens rearrangement) of the best migrating group. Overall, α-substituted α-amino ketones or α-amino esters are formed in one step from simple reactants

Stereochemistry and thermal stability of diazodiketones

The thermal stability of diazodiketones strongly depends on the twisting of the molecular framework caused by steric interaction of substituents at the carbonyl groups. On going from planar cyclic 2-diazo-4, 4-dimethyltetralin-1,3-dione to sterically congested mesitoylpivaloyldiazomethane the rate of decomposition increases 100 times. On the other hand, bulky substituents also decrease the reactivity of 2-ketoketenes formed in the Wolff rearrangement of these diazocarbonyl compounds.

A new rhodium(II) phosphate catalyst for diazocarbonyl reactions including asymmetric synthesis

A new homochiral Rh(II) complex, Rh{HCO3}2{(+)-phos}2·5H2O, where (+)phosH represents (S)-(+)-1,1′-binaphthyl-2,2′-diyl hydrogen phosphate, has been prepared and used as a catalyst for reactions of diazocarbonyl compounds leading to enantioselective 2,3-sigmatropic rearrangement (first example), CH insertion and aromatic cycloaddition

Rh 2(OAc) 4-mediated decomposition of diazocarbonyl compounds: A comparison of α-diazo ketones and α-diazo β-keto esters reactivity.

Unsaturated α-diazocarbonyl compounds undergo intramolecular cyclopropanation or carbon-hydrogen bond insertion when catalyzed by Rh 2(OAc) 4: α-diazo ketones react preferentially with carbon-carbon doubled bond, whereas closely related α-diazo-β-keto-esters insert into carbon-hydrogen bond.

Synthesis and reactivity of 4-acyl-5-hydroxytriazolines resulting from thermal reaction of aryl and tosyl azides with 2-substituted indane-1,3-diones

Reaction of aryl azides 1 with 2-methylindane-1,3-dione 3 in HMPA at 55 °C results in the formation of fairly stable tricyclic 4-acyl-5-hydroxytriazolines 6 in yields greatly decreasing with decreasing electrophilic character of the aryl azide reactant. Similar reaction of 4-nitrophenyl azide 1a with 2-phenylindanedione 4 affords the corresponding 5-hydroxytriazoline 7a in high isolated yield. Upon photolysis or treatment with trifluoroacetic acid the hydroxytriazolines 6 undergo exclusive decomposition to 2-arylamino-2-methylindanediones 12 through the reactive hydroxyaziridine 19 intermediates. On the other hand, upon thermolysis at 95 °C compounds 6 appear to rearrange preferentially to ring-expanded 2-arylisoquinoline-1,3-diones 13, which are believed to result eventually from Wolff rearrangement of initially formed diazo keto amides. The strongly electrophilic tosyl azide 2 reacts smoothly with 2-methylindanedione 3 in HMPA, at room temperature, to give a mixture of the 2-tosylisoquinoline-1,3-dione 14 and the isomeric 1,4-dione 17 to a comparable extent. Under similar conditions, the azide 2 reacts with 2-phenylindanedione 4 to give exclusively the isoquinoline-1,3-dione 15 in virtually quantitative yield. The products 14, 17 and 15 are ascribable to intramolecularly acid-catalysed decomposition of unstable diazocarbonyl compounds resulting from isomerization of reactive 5-hydroxy-1-tosyltriazolines adducts. An X-ray crystal structure analysis of the 4-acyl-5-hydroxytriazoline 6c has been performed.

A Convenient Preparation of Diazo Carbonyl Compounds Under Tri-Phase Phase-Transfer Catalysis Conditions

Abstract A simple and convenient one-pot preparation method for pure diazo carbonyl compounds under tri-phase phasetransfer catalysis conditions is described.

HALOSUBSTITUTED 1,4-OXATHIOCINES. PREPARATION FROM THIOPHENE S,C-YLIDES AND STUDIES OF THERMAL REACTIVITY

Abstract The reaction between tri- and tetrasubstituted thiophenes and diazocarbonyl compounds gave in most cases the corresponding 1,4-oxathiocines directly, without isolation of the intermediate C-S ylides. Two oxathiocines underwent thermal fragmentation leading to sulfur extrusion and the formation of tetra-substituted phenols. A mechanism for the fragmentation is proposed and discussed.

Regiocontrol by the carbon-carbon double bond in the Rh 2(OAc) 4 mediated carbon-hydrogen insertion of α-diazo-ketones.

Diazo carbonyl compounds when catalyzed by dirhodium tetraacetate insert to alylic position. This phenomenon was exploited in cyclic systems 3d 5d 5g and 10. The reactivity toward allylic insertion is corroborated by the unexpected six-membered ring cyclization in the transformation 5g → 9.

Rhodium (II) catalyzed reactions of diazo-carbonyl compounds

Rhodium (II) catalyzed reactions of diazo-carbonyl compounds

Formation of 1,3-Oxathiole-2-thione and 1,2,4-Trithiolane Derivatives by the Catalytic Reaction of α-Diazocarbonyl Compounds with Carbon Disulfide

Abstract The rhodium(II) acetate-catalyzed decomposition of α-diazocarbonyl compounds such as substituted α-diazoacetophenones, cyclic diazoketones, cyclic diazodiketones, and α-diazo-β-ketoesters in carbon disulfide gave 1,3-oxathiole-2-thione derivatives in good yields. Diazomalonates also gave alkyl 5-alkoxy-2-thioxo-1,3-oxathiole-4-carboxylates together with 3,5-bis[bis(alkoxycarbonyl)methylene]-1,2,4-trithiolanes. The formation of 1,3-oxathiole-2-thiones can be explained by the intermediacy of zwitterionic intermediate containing rhodium(II) acetate formed by the reaction of carbon disulfide with ketocarbenoids generated in the catalytic decomposition of the diazocarbonyl compounds.

ChemInform Abstract: Potassium Fluoride on Alumina: An Easy Preparation of Diazocarbonyl Compounds.

AbstractThe carbonyl compounds (I), (V), and (VII) with activated α‐methylene groups are converted to the corresponding diazo compounds (III), (VI), and (VIII) upon treatment with tosyl azide (II) in the presence of potassium fluoride on alumina.

ChemInform Abstract: Multifunctional α‐Trifluoromethyl‐Substituted α‐Hydroxy Acid Derivatives from Trifluoropyruvic Acid Esters and Diazocarbonyl Compounds.

ChemInform Abstract: Multifunctional α‐Trifluoromethyl‐Substituted α‐Hydroxy Acid Derivatives from Trifluoropyruvic Acid Esters and Diazocarbonyl Compounds.

Enantioselectively catalyzed intramolecular cyclopropanations of unsaturated diazo carbonyl compounds

A series of unsaturated α-diazo carbonyl compounds underwent enantioselective intramolecular cyclopropanation (ee = 4–77%) when treated with an enantiomerically pure chiral copper catalyst. The nature of the diazo substrate was critical: α-diazo ketones gave the best enantioselectivities whereas α-diazo β-keto ester systems showed diminished enantioselectivities.

Synthesis of allenes by [2,3]-sigmatropic rearrangement of prop-2-yn-1-yl oxonium ylides formed in rhodium(II) carboxylate catalysed reactions of diazo compounds

High oxophilicity of metal carbenes formed in rhodium(II) perfluorobutyrate catalysed decomposition of diazo carbonyl compounds allows selective ylide generation from methyl prop-2-yn-1-yl ethers with resulting allene production through the [2,3]-sigmatropic rearrangement.

Potassium Fluoride on Alumina: An Easy Preparation of Diazocarbonyl Compounds

Abstract A convenient synthesis of diazocarbonyl compounds from tosyl azide and carbonyl compounds with Al2O3-KF as solid base is reported.

Rhodium acetate catalyzes the addition of carbenoids α- to ether oxygens

Diazo-carbonyl compounds, when catalzed by rhodium acetate, insert preferentially adjacent to ether oxygens. This phenomenon was exploited to develop a synthesis of 3(2H)-furanones.

ChemInform Abstract: Condensation of a Chiral Tetrahydro‐2‐furanthione with Diazocarbonyl Compounds.

Condensation de benzyloxymethyl-5 perhydro furanne-thione-2 avec des diazoesters et diazocetones en presence de Rh 2 (OAc) 4 : obtention des produits de substitution du groupe diazo par [benzyloxymethyl-5 perhydro furylidene-2]

ChemInform Abstract: Synthesis and Reactions of Diazocarbonyl Compounds. Part 2. Reaction of Amino‐1‐diazoalkan‐2‐ones with Electrophilic Agents.

AbstractThe reactions of the aminodiazoketones (I) with electrophilic agents, such as the anhydrides (II), various acid chlorides (e.g.

Copper (II) Supported on Nafion® Perfluorinated Ion Exchange Polymer: An Efficient Catalyst For Cyclopropanation Reactions

Abstract The generation of reactive carbenoid intermediates by transition metal-catalyzed decomposition of α -diazo carbonyl compounds is a rapidly developing area of synthtic methodology. Addition of such species to olefins affords cyclopropane-carboxylate esters such as 1 which has been widely used in organic synthesis 1 and synthetic pyrethroid insecticides 2. Moreover, addition of such carbenoids to C-H and N-H bonds provides stereocontrolled access to products ranging from steroids3 to thienamycin derivatives 4.

Facile catalytic methods for intermolecular generation of allylic oxonium ylides and their stereoselective [2,3]- sigmatropic rearrangement

Allylic oxonium ylides, generated by rhodium(II) acetate-catalyzed decomposition of diazo carbonyl compounds in the presence of allyl methyl ethers, undergo the [2,3]-sigmatropic rearrangement with a high degree of diastereoselectivity.