3aH-indenes and their heterocyclic analogues

Rees, Charles W.

doi:10.1351/pac197951061243

Pure and Applied Chemistry

1979

DOI: 10.1351/pac197951061243

|View full text |Cite

3aH-indenes and their heterocyclic analogues

Charles W. Rees¹

Abstract: Abstract-Whilst studying the use of sulphimides,RN=SMe2, in heterocyclic synthesis we found that N-arylamidinosulphimides can be cleaved photolytically to give imidoylnitrenes-which then cycl ise to benzimidazoles. When both ortho positions of the N-aryl group are substituted, cycl isation still occurs to give a variety of products derivedby rearrangement of the initiaiiY. formed 3aH-benzimidazole; skeletal rearrangernents, (1, 5]-, and the rare (1, 9]-sigrnä'tropic shifts are proposed. When

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

1979

2009

Publication Types

Select...

Article5

Relationship

Self Cite0

Independent5

Authors

Journals

Cited by 7 publications

References 21 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

Indolenine oxides, IX. Novel polycyclic linearly conjugated cyclohexadiene imines from rearrangement of unstable tetrahydroisoxazolo[2,3‐a]‐indoles

1985

View full text Add to dashboard Cite

From 3,3-dipolar cycloaddition of the symmetrically substituted olefins 2 a -e to the sterically overcrowded nitrone 6 , the primary cycloadducts, i.e. the 2,3,3a,4-tetrahydroisoxazolo[2,3-a]-indoles 7a-e, are obtained only by direct crystallization from the chilled reaction mixtures in the absence of acid. Upon storage of the solutions at room temperature, especially in the presence of catalytic quantities of acid, or during chromatography on silica gel, 7a, c -e undergo rearrangement to the cyclohexadiene imines 8a,c-e. The latter in turn are of limited stability in solution and are transformed into indolines or derivatives of 3H-indole under partial removal of the epoxyethano bridge. The structure of 8a has unambiguously been proven by X-ray crystallography. -The analogous primary cycloadducts 3 a -d of the sterically non crowded nitrone 1 are stable and -with one exception in very low yield -do not undergo the rearrangement reported for 7a,c-e. Indoleninoxide, IX 1) Neuartige polycyclische linear konjugierte Cyclohexadienimine durch Umlagerung instabiler Tetrahydroisoxazolo[2,3-n]indole*~~b)Bei der 1,3-dipolaren Cycloaddition der symmetrisch substituierten Olefine 2 a -e an das sterisch uberbeanspruchte Nitron 6 werden die primaren Cycloaddukte, die 2,3,3a,4-Tetrahydroisoxazolo[2,3-a]indole 7 a -e nur erhalten, wenn sie in Abwesenheit von Saure aus den gekuhlten Reaktionsansatzen direkt auskristallisieren. Beim Aufbewahren der Losungen bei Raumtemperatur, insbesondere bei Anwesenheit katalytischer Mengen Saure, oder bei der Chromatographie an Kieselgel wandeln sich 7a, c -e in die Cyclohexadienimine 8a, c -e um. Letztere sind in Losung ebenfalls nur begrenzt haltbar und gehen teilweise unter Abbau der Epoxyethanobrucke in Indolin-oder 3H-Indolderivate uber. Die Konstitution von 8a wurde durch Rontgenstrukturanalyse bewiesen. -Die analogen primaren Cycloaddukte 3a -d des sterisch nicht uberbeanspruchten Nitrons 1 sind stabil und zeigen -mit einer in sehr niedriger Ausbeute verlaufenden Ausnahme -die fur 7a,c -e beschriebene Umlagerung nicht.1,3-Dipolar cycloadditions of nitrones are well known3). Therefore, the easily accessible 3H-indole 1-oxides 14a) and 64b) were subjected to cycloaddition to a variety of dipolarophiles2)

show abstract

Indolenine oxides, IX. Novel polycyclic linearly conjugated cyclohexadiene imines from rearrangement of unstable tetrahydroisoxazolo[2,3‐a]‐indoles

1985

View full text Add to dashboard Cite

show abstract

Photochemische Stickstoff‐Eliminierung aus 1,4‐Dihydro‐1‐phenyl‐5H‐tetrazol‐5‐onen und ‐thionen. Benzimidazolone und Carbodiimide

Quast

Nahr

1985

Chem. Ber.

View full text Add to dashboard Cite

Durch photochemische Stickstoff-Extrusion aus Tetrazolonen 1 rnit ungesattigten Substituenten erhalt man die Diaziridinone 2 (n = 1 -3)2) und im Falie des I-Vinyltetrazolons 1 (n = 0) Folgeprodukte der 1,5-Cyclisierung (3, 4) und der SolvensAddition (5) einer Photo~wischenstufe~).Beim Bestrahlen der Tetrazolthione werden dagegen Stickstoff und Schwefel eliminiert, wobei Carbodiimide entstehen2v4). Es war nun naheliegend zu untersuchen, wie Phenylgruppen das photochemische Geschehen beeinflussen. So kdnnte zum Beispiel bei der 1,5-Cyclisierung der durch Stickstoff-Extrusion gebildeten Zwischenstufe ein 1-Phenylring rnit einer 4-Vinylgruppe konkurrieren, was zu Benzimidazolen fuhren 0 VCH Verlagsgesellschaft mbH, D

show abstract

Photochemische Stickstoff‐Eliminierung aus phenylsubstituierten 1,4‐Dihydro‐5‐imino‐5 H ‐tetrazolen. Folgeprodukte phenylsubstituierter Tris(imino)methan‐Diradikale

1985

View full text Add to dashboard Cite

Aus den 5-(Methylthio)tetrazoliumsalzen 11 und primaren Aminen werden die phenylsubstituierten 5-Iminotetrazole 7 b -h hergestellt. Im Gegensatz zur ElektronenstoR-induzierten Fragmentierung im Massenspektrometer beobachtet man beim Belichten der 5-Iminotetrazole 7 b -g keine der denkbaren Isomerisierungen 7 b + 7c, 7f + 7i, 7d + 7 e und 7g -+ 7 j sondern nur Verlust von Stickstoff. Dabei entstehen hauptsachlich 2-Aminobenzimidazole 8 neben geringen Mengen Guanidin 12 und -im Falle der 5-Iminotetrazole 7d, e mit zwei Phenylgruppen -ca. Products of Phenyl-Substituted Tris(imin0)methane Diradicals 1)The reaction of 5-(methy1thio)tetrazolium salts 11 with primary amines produces the phenyl-substituted 5-iminotetrazoles 7 b -h. In contrast to the results of the electron impact-induced fragmentation in the mass spectrometer, irradiation of the 5-iminotetrazoles 7b -g does not effect the possible isomerizations 7b t 7c, 7f + 7i, 7d --7e and 7g + 7j, but only loss of molecular nitrogen. Thus, 2-aminobenzimidazoles 8 are formed as major photo products, besides small amounts of the guanidines 12 and 10% 2-aminodibenzo-1,3-diazepine 16a in the case of the 5-iminotetrazoles 7d, e bearing two phenyl substituents. From each isomer of the pairs 7b, c and 7d, e the same ratio of the photo products 8a, 12a and 8b, c, 12b, 16a, respectively, is obtained. Irradiation of the deuterium labelled 5-iminotetrazoles 7f and g leads to complete scrambling of the deuterium over the possible positions in the photo products. The results demonstrate that the ring nitrogen atoms N-I and N-4 and the exocyclic nitrogen atom become equivalent with respect to product formation. Phenyl-substituted tris(imin0)methane diradicals 22, produced via photo extrusion of molecular nitrogen from the 5-iminotetrazoles 7b -g, are postulated as fully equilibrated intermediates.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

3aH-indenes and their heterocyclic analogues

Cited by 7 publications

References 21 publications

Indolenine oxides, IX. Novel polycyclic linearly conjugated cyclohexadiene imines from rearrangement of unstable tetrahydroisoxazolo[2,3‐a]‐indoles

Indolenine oxides, IX. Novel polycyclic linearly conjugated cyclohexadiene imines from rearrangement of unstable tetrahydroisoxazolo[2,3‐a]‐indoles

Photochemische Stickstoff‐Eliminierung aus 1,4‐Dihydro‐1‐phenyl‐5H‐tetrazol‐5‐onen und ‐thionen. Benzimidazolone und Carbodiimide

Photochemische Stickstoff‐Eliminierung aus phenylsubstituierten 1,4‐Dihydro‐5‐imino‐5 H ‐tetrazolen. Folgeprodukte phenylsubstituierter Tris(imino)methan‐Diradikale

Contact Info

Product

Resources

About