1,3-Dipolar cycloadditions of diphenyldiazomethane to thioketones: Rate measurements disclose thiones to be superdipolarophiles

Huisgen, Rolf; Langhals, Elke

doi:10.1002/hc.20262

Cited by 36 publications

(25 citation statements)

References 47 publications

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“…That brings us back to the original observation of the exceptional stability of 10 among the cycloadducts of diphenyldiazomethane which lose N 2 rapidly [1]. What is the rate ratio for the formation of 10 and its N 2 extrusion ?…”

Section: Several Pathways Of Cycloreversionmentioning

confidence: 93%

“…• C furnishes tetrasubstituted 2,5-dihydro-1,3,4-thiadiazoles 6 [1]; as a consequence of substitution by phenyl, they eliminate N 2 in a fast subsequent cycloreversion. There was one exception among 16 studied examples: the adduct 10 resulting from 8 and 2,2,6,6-tetramethylcyclohexanethione (7) was isolable (Scheme 2).…”

Section: Methodsmentioning

confidence: 99%

“…General [1] 2,2,6,6-Tetramethylcyclohexanethione (7) and Diphenyldiazomethane (8). 6,6,10, [4.5]dec-1-ene (10).…”

Section: Methodsmentioning

confidence: 99%

“…The conversion of 10 to 12 + 13 is rate determining, and 14 has at the beginning the advantage of a higher concentration (1.1 equivalents with respect to 10) in the competition for 13; the concentration of thiobenzophenone would build up and reach [12] = [14] = 0.55 equivalent after 90% reaction. However, a high ratio k d /k −c is inherently improbable, since 12 is 2.2 times more reactive than 14 in the cycloaddition with diphenyldiazomethane (8) [1].…”

Section: Several Pathways Of Cycloreversionmentioning

confidence: 99%

“…The gain in bond energy during the conversion of the cyclic azo compound 1 into the N 2 molecule affords the thermodynamic driving force, but also the substituted thiocarbonyl ylide (2) affects the energy level of the transition state (TS), as summarized in the preceding paper [1].…”

Section: Introductionmentioning

confidence: 99%

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Dichotomy of 1,3-dipolar cycloreversions in a tetrasubstituted 2,5-dihydro-1,3,4-thiadiazole

Langhals

Huisgen

2006

Heteroatom Chem.

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Section: Several Pathways Of Cycloreversionmentioning

confidence: 93%

Section: Methodsmentioning

confidence: 99%

“…General [1] 2,2,6,6-Tetramethylcyclohexanethione (7) and Diphenyldiazomethane (8). 6,6,10, [4.5]dec-1-ene (10).…”

Section: Methodsmentioning

confidence: 99%

Section: Several Pathways Of Cycloreversionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dichotomy of 1,3-dipolar cycloreversions in a tetrasubstituted 2,5-dihydro-1,3,4-thiadiazole

Langhals

Huisgen

2006

Heteroatom Chem.

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Twofold Extrusion Reactions

Guziec

2012

Organic Reactions

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Twofold extrusion reactions are chemical transformations in which two small inorganic molecules or atoms connecting carbon or nitrogen atoms are lost, generating the corresponding carbon‐carbon or carbon‐nitrogen double bonds. These reactions are particularly useful for the preparation of sterically hindered alkenes and imines. The inorganic species liberated in twofold extrusion reactions can be molecular nitrogen, sulfur, selenium, tellurium, sulfur dioxide, sulfur monoxide, carbon dioxide or carbon monoxide. The most common precursors for twofold extrusion reactions are 1,3,4‐thiadiazolines, which thermally extrude molecular nitrogen affording thiiranes. These thiiranes can be readily desulfurized to afford the corresponding alkenes using tertiary phosphines. The corresponding 1,3,4‐selenadiazolines thermally extrude both molecular nitrogen and atomic selenium directly affording alkenes. Alkenes can also be prepared by formal extrusions of molecular nitrogen plus sulfur dioxide or sulfur monoxide. Extremely sterically hindered imines can be prepared by extrusions of molecular nitrogen and sulfur or selenium from in situ generated heterocyclic precursors. Other less common twofold extrusion reactions are also reported. The detailed preparations of the required precursors for the twofold extrusion reactions as well as the mechanisms of these extrusion processes are discussed in this chapter. The utility of twofold extrusion reactions in the preparations of ‘molecular rotors’ and other extremely sterically hindered alkenes is presented. The steric limitations of the twofold extrusion reactions are discussed along with comparisons of these reactions with other alkene‐ and imine‐forming synthetic methods. The Tabular Survey covers material through the end of 2009.

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Reactions of Cycloaliphatic Thioketones and Their Oxo Analogues with Lithiated Methoxyallene: A New Approach to Vinylthiiranes

Jasiński

Mlostoń

Stolarski

et al. 2014

Chemistry An Asian Journal

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Admantanethione smoothly reacted with lithiated methoxyallene at low temperatures yielding the expected allenyl-substituted thiolate, which upon aqueous work-up underwent spontaneous 1,3-cyclization to afford a hitherto unknown methoxy-substituted vinylthiirane derivative. The analogous reaction with adamantanone led to the corresponding allenyl alcohol that can be isolated and--depending on the conditions applied--either be converted into the corresponding vinyloxirane or into the 2,5-dihydrofuran derivative. Sterically more crowded thioketones were also combined with lithiated methoxyallene, but in these cases competitive 1,5-cyclization leading to isomeric dihydrothiophene derivatives was observed. DFT calculations of model intermediates and products show distinct energy differences of the sulfur and the corresponding oxygen compounds. Desulfurization of the adamantanethione-derived vinylthiirane yielded a methoxy-substituted 1,3-diene that was studied in cycloadditions with electron-deficient dienophiles. Whereas in the case of tetracyanoethylene the corresponding cyclobutane derivative was formed, the reaction with nitrosobenzene provided the expected 1,2-oxazine derivative. By reductive cleavage of the N-O bond this heterocycle was converted into an unsaturated amino alcohol bearing an adamantane moiety.

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1,3-Dipolar cycloadditions of diphenyldiazomethane to thioketones: Rate measurements disclose thiones to be superdipolarophiles

Cited by 36 publications

References 47 publications

Dichotomy of 1,3-dipolar cycloreversions in a tetrasubstituted 2,5-dihydro-1,3,4-thiadiazole

Dichotomy of 1,3-dipolar cycloreversions in a tetrasubstituted 2,5-dihydro-1,3,4-thiadiazole

Twofold Extrusion Reactions

Reactions of Cycloaliphatic Thioketones and Their Oxo Analogues with Lithiated Methoxyallene: A New Approach to Vinylthiiranes

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