Strained aromatic systems. Synthesis of cyclopropabenzocyclobutenes, cyclopropanaphthocylobutenes, and related compounds

Davalian, Dariush; Garratt, Peter J.; Koller, Wolfgang; Mansuri, Muzammil M.

doi:10.1021/jo01309a024

Cited by 36 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mixture was refluxed for 2 h. Excess LiAIH, was decomposed by addition of 50 g of ice. Workup yielded 19 (8. (7,heptane -3,4-di~~l)dimethyl Bisjinethanesulfonatej (20) [3] [15]. MsCl (4.7 g, 58.5 mmol) in CH2CI2 (20 ml) was added slowly to a stirred soln.…”

Section: Experimental Partmentioning

confidence: 99%

“…3,3a,4,7,dro-l H-indune-I,3-dione (8) [9]. Buta-1,3-diene (4.40 g, 81.5 mmol) and 7 (2.0 g, 20.8 mmol) were stirred in 5M LiCIO, in Et,O (50 ml) in an autoclave for 72 h at 25".…”

Section: -Dihydro-1 H3h-cycloprop[ F]indene-44-dicarboxylate (26)mentioning

confidence: 99%

“…Both approaches use aromatization of an appropriate 1,l-dichlorocyclopropane in the last step. The synthesis of 1 is based on the construction of the tricyclic skeleton starting with synthon 4, which has been used in the past as building block for cycloproparenes [3] [4] (Scheme I ) . The ring system 5 is constructed by condensation of a one-atom fragment derived from malonate.…”

mentioning

confidence: 99%

“…By the second approach, first the functionalized indane system 8 is constructed by cycloaddition of butadiene to cyclopent-The synthesis of 1 is outlined in Scheme 3. The synthon 4 was prepared according to the sequence described in [3] with only minor modifications: addition of dichlorocarbene, generated under phase-transfer conditions (CHCl, and conc. NaOH in the presence of (benzyl)(triethyl)ammonium chloride) to diethyl cis-cyclohexene-4,5-dicarboxylate (17) furnished 18 as a single stereoisomer which was reduced with LiAIH, to afford the dioll9.…”

mentioning

confidence: 99%

“…115 (23), 91 (16), 79 (22). 65 (11).7,7-Dichloro-3,4-dimethylidenebicyc"4fane (4)[3]. To a stirred soln.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Synthesis of Functionalized Cycloprop[f]indenes via the Carbene Addition Route

Müller¹,

Miao²

1994

Helvetica Chimica Acta

View full text Add to dashboard Cite

The synthesis of4,5-dihydro-1H,3H-cycloprop[flinden-4-ol (I) and diethyl4,S-dihydro-1 H,3H-cycloprop[flindene-4,4-dicarboxylate (26) starting from dime 4 is described. The cyclopentene ring is constructed by condensation of diethyl malonate to the dibromide 21. The key-step in the synthesis of 1 consists in a twofold Curtius degradation of 22, with subsequent reduction of the carbonyl group and aromatization. The skeleton of the isomer 31 is synthesized via cycloaddition of butadiene to cyclopent-4-ene-l,3-dione (7) and addition of dichlorocarbene to the adduct 27 after ketalisation. The attempted synthesis of dihydrocycloprop[flindene (2) by base-induced elimination of several appropriately substituted precursors failed.HELVETICA CHIMICA ACTA ~-Vol. 77 (1994) Scheme I 7 8 9 4-ene-1,3-dione (7). Addition of dichlorocarbene followed by functional-group modification and aromatization of the adduct 9 as above should lead directly to 2. Resultsand Discussion. ~ Synthesis of 4,s-Dihydro-I H,3H-cycloprop[ f/inden-4-01(1) j r o m 4. The double Curtius degradation of geminal diesters, which is the key step in the proposed synthesis of 1, has been used only once in the literature [6]. Model studies were carried out in order to establish the feasibility of the approach in our system. 1,2-Bis(bromomethy1)benzene (10) was condensed with diethyl malonate [7] to afford 11, which was hydrolyzed [8] to the diacid 12 (Scheme 2). Reaction of 12 with oxalyl chloride afforded the dichloride 13, and treatment of the latter with NaN, in MeCN at 25" led to the azide 14. The azide was rearranged to the bis-isocyanate 15 by refluxing in cyclohexane. Hydrolysis of the crude 15 afforded indan-2-one (16) in 45-50% overall yield. 10 11 X = EtO 12 X = O H 13 X=C1 14 X = N , 15 X = NCO 16 X,X = 0

show abstract

Section: Experimental Partmentioning

confidence: 99%

“…3,3a,4,7,dro-l H-indune-I,3-dione (8) [9]. Buta-1,3-diene (4.40 g, 81.5 mmol) and 7 (2.0 g, 20.8 mmol) were stirred in 5M LiCIO, in Et,O (50 ml) in an autoclave for 72 h at 25".…”

Section: -Dihydro-1 H3h-cycloprop[ F]indene-44-dicarboxylate (26)mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…115 (23), 91 (16), 79 (22). 65 (11).7,7-Dichloro-3,4-dimethylidenebicyc"4fane (4)[3]. To a stirred soln.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Synthesis of Functionalized Cycloprop[f]indenes via the Carbene Addition Route

Müller¹,

Miao²

1994

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

Cycloproparenes

Halton

2009

Patai's Chemistry of Functional Groups

View full text Add to dashboard Cite

Introduction Synthesis of Cycloproparenes Physical and Theoretical Aspects of Cycloproparenes Cycloproparenyl Cations, Anions and Radicals Reactions of Cycloproparenes Oxo‐ and Alkylidenecycloproparene Chemistry Acknowledgements

show abstract

Cobalt-vermittelte [2+2+2]-Cycloadditionen: eine ausgereifte Synthesestrategie

Vollhardt

1984

Angew. Chem.

328

View full text Add to dashboard Cite

Dicarbonyl(q5-cyclopentadienyl)cobalt wirkt als Matrize, an der eine Vielzahl ungesiittigter organischer Spezies miteinander Bindungen bildet. Auf diese Weise konnen a,o-Diine mit Monoalkinen zu anellierten Benzolderivaten cocyclisieren, o-Diethinylbenzol liefert Biphenylene, und a,o-Enine ergeben komplexierte bi-und tricyclische Diensysteme. Nitrile cocyclisieren mit Alkinylgruppen zu Pyridinen und anderen Heterocyclen, Isocyanate fiihren zu anellierten 2-Pyridonen, wahrend die Inkorporation von Kohlenmonoxid den Zugang zu komplexierten Cyclopentadienonen eroffnet. In vielen Fallen verlaufen diese Reaktionen mit bemerkenswerter Chemo-, Regio-und Stereoselektivittit, die zum Teil durch Trimethylsilylsubstituenten als kontrollierende und dirigierende Gruppen ermoglicht werden. Anwendungsbereich und Ausgereiftheit dieser Methode werden an der Synthese bisher nicht zuganglicher, neuartiger und theoretisch interessanter Molekiile und dariiber hinaus einer Vielfalt von Naturstoffen demonstriert, z. B. Protoberberinen, Steroiden, Vitamin B6 Schema I. Polyencyclisierung nach Johnson et al. 121 Angew. Chem. 96 (1984) S2S-541 8 Verlag Chemie GmbH. 0-6940 Weinheim. 1984 0044-8249/84/0808-OSZS S O.?.SO/O 2. Cyclisierungen von a,w-Diinen bei der Synthese anellierter Benzol-Derivate : Steuerung des Substitutionsmusters 2.1. Hintergrund Berthelot berichtete 1866 erstmals iiber die thermische Cyclisierung von Acetylen zu Benzol["]. Hohe Temperaturen (ca. 400°C) sind dabei erforderlich, und es entsteht ein Produktgemisch["I. Reppe et al. beschrieben 1949 die erste Ubergangsmetall(Nicke1)-katalysierte Umwandlung dieser Art, welche unter bestimmten Bedingungen iiberwiegend zu Cyclooctatetraen fiihrt[l2]. In der Folgezeit wurden sehr viele Ubergangsmetallkomplexe gefunden, die die Cyclotrimerisierung substituierter und haufig auch funktionalisierter Alkine zu Benzol-Derivaten kataly~ieren"~'. Obwohl solche Reaktionen ein betrachtliches Potential fur den Aufbau komplizierter Molekiile haben, wuBte man zu Beginn der hier beschriebenen Arbeiten verhaltnismii-Big wenig iiber die nutzbringende Anwendung dieses Reaktionstypsinsbesondere unter Beteiligung von Oligoinenin der organischen Synthese. Der Wert dieser Reaktionen war in der Tat schon friiher erkannt worden, als man fand, dal3 eine Vielzahl oligocyclischer Systeme durch Cyclisierung von a,w-Diinen erhaltlich ist[14]. Dariiber hinaus zeigten Miiller et al. in iiber vierzig Veroffentlichungen, daD mit stochiometrischen Anteilen von Rhodiumkomplexen durch die ,,Diinreaktion" Rhodacyclen mit abgestufter Reaktivitat hergestellt werden konnen, die sich in Chinone, Carbo-und Heterocyclen umwandeln la~sen['~]. Obwohl diese Methode beziiglich Anwendungsbreite, Allgemeingiiltigkeit und Kostenaufwand Grenzen hat, wies sie doch auf zukiinftige Moglichkeiten hin. Seit kurzer Zeit interessieren sich auch andere Arbeitsgruppen fur diese Probleme[161.9 Schema 6. Selcktive elektrophile aromatische Substitution von o-Bis(trime-thylsi1yl)arenen.Ein anderes interessantes Charakteristikum der Verbind...

show abstract

Strained aromatic systems. Synthesis of cyclopropabenzocyclobutenes, cyclopropanaphthocylobutenes, and related compounds

Cited by 36 publications

References 0 publications

Synthesis of Functionalized Cycloprop[f]indenes via the Carbene Addition Route

Synthesis of Functionalized Cycloprop[f]indenes via the Carbene Addition Route

Cycloproparenes

Cobalt-vermittelte [2+2+2]-Cycloadditionen: eine ausgereifte Synthesestrategie

Contact Info

Product

Resources

About