Photochemical transformations of small ring heterocyclic compounds. LXV. 1,1-Cycloaddition from a 1,3-dipole

Padwa, Albert; Carlsen, Per H. J.

doi:10.1021/ja00846a076

Cited by 34 publications

(33 citation statements)

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“…[4,33] Nevertheless, there is also some evidence for carbene-like behavior of some nitrile ylide derivatives, as expressed through formation of [21] cycloaddition products. [35] Moreover, our results here could also be explained in terms of an initial [21] cycloaddition giving 2H-azirene [6] or oxirane derivatives, respectively, with subsequent ring enlargement.…”

Section: Resultsmentioning

confidence: 63%

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

et al. 1998

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Thermal ring-opening of {[2-bis(trimethylsilyl)methyl-3-phenyl-2H-azaphosphirene-kP]pentacarbonyltungsten(0)} (1) in the presence of various nitriles is investigated, in which toluene and/or the nitriles are used as solvents. In toluene, for example, the 3-(1-piperidino)-substituted 2H-azaphosphirene complex 5 b, 4-(1-piperidino)-5-phenyland 4,5-bis(1-piperidino)-substituted 2H-1,3,2-diazaphosphole complexes 6b,d are obtained if 1-piperidino nitrile (2 b) is employed as trapping reagent. Furthermore, a new three-component reaction is presented, using the 2H-azaphosphirene complex 1 and a mixture of two different nitriles, thus giving access to 4,5-mixed-substituted 2H-1,3,2-diazaphosphole complexes 6 a, b and 6 e ± h.The chemo-and regioselectivity of such reactions is rationalized by [32] cycloadditions of transiently formed C-dialkylamino-substituted nitrilium phosphane ylide complexes 3 b, c to nitriles. Use of two equivalents of dialkyl cyanamides and four equivalents of either ethyl cyanoformate or phenyl glyoxonitrile resulted in dual trapping reactions of complexes 3 b, c, forming 2H-1,3,2-diazaphosphole complexes 6 i ± k and D 3 -1,3,2-oxazaphospholene complexes 8 a ± g. Reaction of the 2H-azaphosphirene complex 1 with ethyl cyanoformate in toluene gave exclusively the 4,5-bis-(ethoxycarbonyl)-2H-1,3,2-diazaphosphole complex 6 l; even in benzonitrile, the mixed-substituted 2H-1,3,2-diazaphosphole complex 6 m is formed only as a by-product. The first 2H-1,4,2-diazaphosphole complex 9 was synthesized along with the regioisomeric 2H-1,3,2-diazaphosphole complex 6 n (ratio of 9:6 n: 6:1) through thermal ring-opening of 2H-azaphosphirene complex 1 in neat benzonitrile. The structures of 2H-1,3,2-diazaphosphole complex 6 c, 2R,5S-D 3 -1,3,2-oxazaphospholene complex 8 a and 2H-1,4,2-diazaphosphole complex 9 were determined by single-crystal X-ray diffraction.

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Section: Resultsmentioning

confidence: 63%

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

et al. 1998

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“…Bei dessen Reduktion mit Lithiumalanat lien sich die Bildung des Aminoquadricyclans 5 wahrscheinlich machen. 4 5…”

Section: Das Thermische Verhalten Von 3-aminoquadricyclanenunclassified

Carben‐Reaktionen, XVII. Nitrilylide durch 1,1‐Eliminierung

Hoffmann

Barth

1985

Chem. Ber.

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Das 3-Aminoquadricyclan-3-carbonitril 7 zerfallt bei der Gasphasenthermolyse in Benzol und Cyan(dimethy1amino)carben 15. Die entsprechende Benzylidenverbindung 20 setzt bei der Thermolyse den 1,3-Dipol21 frei, der sich zum 1-Isoindolcarbonitri123 stabilisiert. Das analog freigesetzte Nitrilylid 26 ergab durch intramolekulare 1,3-dipolare Cycloaddition den Bicyclus 27. Carbene Reactions, XVIII)Nitrile Ylides via 1,l-Elimination The 3-amhoquadricyclane-3-carbonitrile 7 decomposed upon vapor phase thermolysis into benzene and cyano(dimethy1amino)carbene 15. Thermolysis of the corresponding benzylidene derivative 20 liberated the 1,3-dipole 21, which eventually leads to 1-isohdolecarbonitrile 23. The nitrile ylide 26 liberated similarly furnished the bicyclic compound 27 via intramolecular 1,3-dipolar addition.Die reichhaltige Chemie der 1 ,3-Dipolez) wurde durch die Beobachtung erweitert, daB Nitrilylide 2 nicht nur als 1,3-Dipole, sondern auch ,,aus der Carben-Grenzstruktur 2' heraus" 3, zu reagieren verm2)gen4).Dieser Reaktionsweise der 1,3-Dipole unter 1,l-Addition an Olefine steht unseres Wissens bisher keine entsprechende Bildungsweise gegenuber, d. h. eine 1,l-Eliminierung, die zu 1,3-Dipolen fuhrt. Wir wollten deswegen prufen, ob Nitrilylide in Bhnlicher Weise wie Carbenes) durch Thermolyse von 7-Amino-substituierten Norbornadienen freisetzbar sind. Zuvor muBte jedoch geklart werden, o b 7-Aminonorbornadiene Llberhaupt eine derartige Cycloeliminierung eingehen, oder o b sie wie 7-Methoxynorbornadien6) oder Norbornadien-7-olate7) thermisch zu CycloheptatrienDerivaten isomerisieren.0 VCH Verlagsgesellschaft mbH, D-6940 Weinheim, 1985

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“…Under acidic (aqueous HC1, THF, 5 min, 0°) or weakly basic (SOCh-pyridine, ether-hexane, -20°) conditions, these substances undergo facile rearrangements9 to produce a-mercapto-a,)3-unsaturated aldehydes 8 (Y = n-C4H9 (60)4 a Unless otherwise indicated the yields were based on products isolated by preparative TLC. 6 The yields were determined by spectral data of the crude products. These adducts were subjected to rearrangement reactions without purification.…”

Section: Rsch=choet Rsc=choetmentioning

confidence: 99%

“…These adducts were subjected to rearrangement reactions without purification. 6 Reaction in THF. 4 Reaction in THF/ HMPA.…”

Section: Rsch=choet Rsc=choetmentioning

confidence: 99%

“…We previously reported that the photolysis of azirine 11 gave azabicyclohexene 16. 6 The formation of the thermodynamically less favored endo isomer from the trans olefin corresponds to a complete inversion of stereochemistry about the C-C double bond in the cycloaddition process. We now find that the thermodynamically less favored endo isomer ( 16) is also formed from the irradiation of azirine 12.13…”

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confidence: 99%

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Photochemical transformations of small ring heterocyclic compounds. 74. A stepwise 1,3-dipolar cycloaddition reaction

Padwa¹,

Carlsen²

1976

J. Am. Chem. Soc.

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3) (a) The synthesis of 1 is described in ref 1. Compound 3 was obtained from 1,4-butanedithiol and dibromomethane in presence of base.48 Bis(vinylmercapto)methane (4) has been synthesized from the reaction of vinyllithium and sulfur in tetrahydrofuran, followed by alkylation of the lithium vinyl thiolate46 with dibromomethane. (b) All new compounds have been fully characterized by their spectral and analytical data. Details will be reported in a full paper. (4) (a) S.

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Photochemical transformations of small ring heterocyclic compounds. LXV. 1,1-Cycloaddition from a 1,3-dipole

Cited by 34 publications

References 3 publications

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

Syntheses of 2H-1,3,2-Diazaphosphole, 2H-1,4,2-Diazaphosphole, and Δ3-1,3,2-Oxazaphospholene Complexes; First Examples of 2H-Azaphosphirene Complex Formation by [2+1] Cycloaddition

Carben‐Reaktionen, XVII. Nitrilylide durch 1,1‐Eliminierung

Photochemical transformations of small ring heterocyclic compounds. 74. A stepwise 1,3-dipolar cycloaddition reaction

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