Abstract:Ein neuartiger, hochgespannter Kohlenwasserstoff, der Tetracyclus (1), wurde aus o‐Divinylbenzol synthetisiert. Die Struktur von (1) ist durch die spektralen Daten gesichert. An (1) kann erstmals die Wechselwirkung der Spiropentan‐Einheit mit dem Benzolring untersucht werden.
“…Up to now, several synthetic approaches to UTs and BTs have been successful. The first members of the CAT family of type 19 ( n = 0, m = 2, 3) have been known since 1962, and more than 20 years later several compounds of type 19 and 20 with more than two spirocyclopropane units were eventually prepared. − Only the cyclo[ n ] triangulanes remain elusive, as there is no communication yet reporting the successful preparation of any CT. Two points can be made in advance: (i) A cyclic triangulane can only be constructed with an even number of three-membered rings and a planar central ring 35a and (ii) according to various calculations [8]CT would be the most realistic and straightforward synthetic target, 35a, yet and [10]CT and [6]CT (“davidane”) 18 should not be impossible despite their excessive strain due to the additional angle distortion in their spiropentane subunits. 2 …”
Section: Triangulanes: Nomenclature Classification
and Stereoisomerismmentioning
confidence: 99%
“…Several synthetic equivalents of cyclopropylidenes have been investigated in detail. 92b,− The most commonly applicable method is the in situ generation of a diazocyclopropane ( 113 ) from the corresponding N -nitrosocyclopropylurea by treatment with a base. The reaction of a dibromocyclopropane with an alkyllithium reagent in the presence of an internal or external double bond 118 has been applied mainly for the preparation of cycloannelated[ n ]triangulanes (see below). − Sulfonium- and sulfoxoniumcyclopropylides 108 and 111 119 have found a limited application in oligospirocyclopropane chemistry, e.g., for the preparation of the spiropentane derivatives 109 and 112 (Scheme ). The highly convergent building block method has been applied to make C 2 v -[6]BT 85 54,55b and C 2 v -[8]BT 116 (Scheme ). ,55b Comparable results were achieved with in situ generated 7-diazodispiro[2.0.2.1]heptane ( 118 ) (Scheme ). , 18 19 20 21 …”
Section: Synthetic Approaches To Branched
Triangulanes (Bts)mentioning
confidence: 99%
“…During the first 15 years after their preparation, these CATs 141 and 143 have received surprisingly little attention. Their renaissance was due to further developments by Brinker et al , and Wiberg et al Not surprisingly, the smallest conceivable cycloannelated spiropentane, the hydrocarbon 144 , turned out to be unstable even at −55 °C. 70f,g The unsubstituted hydrocarbon 145 still remains unknown. A thermochemical study for 146 , photoelectron spectroscopic investigations of 146 and 148 , and structure analyses of 146 , 148 (prepared similarly in 33% yield 67b ), and 149 have been reported (Chart ). 70e, Brinker et al were unable to reproduce Skattebøl's preparation of 147 (≙ 141c , Scheme ) 128a.…”
“…Eventually, this hydrocarbon was authentically prepared indirectly starting from Skattebøl's bridged methylenespiropentane−CST 150 (≙ 143a , Scheme ) by thermal isomerization and reduction with diimide (Scheme ) 128b. Functionally substituted CATs 152 − 155 were also obtained applying Skattebøl's method but in much lower yield (Scheme ). 67a,,70b-e Carbon skeletons of type 147 and 145 were constructed by ring expansion and ring contraction of two-carbon bridged spiropentane derivatives 154 and 158 , respectively. 70b-d 26 7 27 28 …”
“…This latter approach does not need special consideration. Reactions of this type as well as their productstetra- and dibromotriangulanes (for examples, see refs , , , , , , , a,b, 98b, 99, 122a, and 136−141), oligochlorotriangulanes, 96a,b,97a,d,98c,,139a,− mono- and oligoalkyl(aryl)triangulanes 44b,65b,93,98b,103a,b,116d,117b,c,118,122b,148-152 are sufficiently well documented. The abundance of experimental material, especially for spiropentane, the simplest unbranched triangulane [2]UT ( 11 ), makes it virtually impossible to present a concise and simple systematization within the scope of a limited review.…”
I. Introduction 93 II. Triangulanes: Nomenclature, Classification, and Stereoisomerism 94 III. Synthesis of Triangulanes 96 A. Synthetic Methods to Assemble Oligospirocyclopropanes 96 B. Synthesis of Unbranched Triangulanes (UTs) 97 C. Synthetic Approaches to Branched Triangulanes (BTs) 99 D. Cycloannelated Triangulanes (CATs) 102 E. Along the Route to Cyclotriangulanes (CTs) 103 F. Substituted Triangulanes 104 G. Heterotriangulanes 108 IV. Selected Physical Properties of Triangulanes 109 A. Spectral Data 109 B. Bonding Properties and Molecular Structures 110 C. Thermochemical Properties 115 V. Chemical Transformations of Triangulanes 117 A. With Retention of the Skeleton 117 B. With Ring Opening 121 VI. Triangulanes with Properties of Potential Practical Applicability 130 VII. Conclusions and Further Perspectives 133 VIII. Acknowledgments 136 IX. References 136 † Dedicated to Professor Wolfgang Lu ¨ttke on the occasion of his 80th birthday.
“…Up to now, several synthetic approaches to UTs and BTs have been successful. The first members of the CAT family of type 19 ( n = 0, m = 2, 3) have been known since 1962, and more than 20 years later several compounds of type 19 and 20 with more than two spirocyclopropane units were eventually prepared. − Only the cyclo[ n ] triangulanes remain elusive, as there is no communication yet reporting the successful preparation of any CT. Two points can be made in advance: (i) A cyclic triangulane can only be constructed with an even number of three-membered rings and a planar central ring 35a and (ii) according to various calculations [8]CT would be the most realistic and straightforward synthetic target, 35a, yet and [10]CT and [6]CT (“davidane”) 18 should not be impossible despite their excessive strain due to the additional angle distortion in their spiropentane subunits. 2 …”
Section: Triangulanes: Nomenclature Classification
and Stereoisomerismmentioning
confidence: 99%
“…Several synthetic equivalents of cyclopropylidenes have been investigated in detail. 92b,− The most commonly applicable method is the in situ generation of a diazocyclopropane ( 113 ) from the corresponding N -nitrosocyclopropylurea by treatment with a base. The reaction of a dibromocyclopropane with an alkyllithium reagent in the presence of an internal or external double bond 118 has been applied mainly for the preparation of cycloannelated[ n ]triangulanes (see below). − Sulfonium- and sulfoxoniumcyclopropylides 108 and 111 119 have found a limited application in oligospirocyclopropane chemistry, e.g., for the preparation of the spiropentane derivatives 109 and 112 (Scheme ). The highly convergent building block method has been applied to make C 2 v -[6]BT 85 54,55b and C 2 v -[8]BT 116 (Scheme ). ,55b Comparable results were achieved with in situ generated 7-diazodispiro[2.0.2.1]heptane ( 118 ) (Scheme ). , 18 19 20 21 …”
Section: Synthetic Approaches To Branched
Triangulanes (Bts)mentioning
confidence: 99%
“…During the first 15 years after their preparation, these CATs 141 and 143 have received surprisingly little attention. Their renaissance was due to further developments by Brinker et al , and Wiberg et al Not surprisingly, the smallest conceivable cycloannelated spiropentane, the hydrocarbon 144 , turned out to be unstable even at −55 °C. 70f,g The unsubstituted hydrocarbon 145 still remains unknown. A thermochemical study for 146 , photoelectron spectroscopic investigations of 146 and 148 , and structure analyses of 146 , 148 (prepared similarly in 33% yield 67b ), and 149 have been reported (Chart ). 70e, Brinker et al were unable to reproduce Skattebøl's preparation of 147 (≙ 141c , Scheme ) 128a.…”
“…Eventually, this hydrocarbon was authentically prepared indirectly starting from Skattebøl's bridged methylenespiropentane−CST 150 (≙ 143a , Scheme ) by thermal isomerization and reduction with diimide (Scheme ) 128b. Functionally substituted CATs 152 − 155 were also obtained applying Skattebøl's method but in much lower yield (Scheme ). 67a,,70b-e Carbon skeletons of type 147 and 145 were constructed by ring expansion and ring contraction of two-carbon bridged spiropentane derivatives 154 and 158 , respectively. 70b-d 26 7 27 28 …”
“…This latter approach does not need special consideration. Reactions of this type as well as their productstetra- and dibromotriangulanes (for examples, see refs , , , , , , , a,b, 98b, 99, 122a, and 136−141), oligochlorotriangulanes, 96a,b,97a,d,98c,,139a,− mono- and oligoalkyl(aryl)triangulanes 44b,65b,93,98b,103a,b,116d,117b,c,118,122b,148-152 are sufficiently well documented. The abundance of experimental material, especially for spiropentane, the simplest unbranched triangulane [2]UT ( 11 ), makes it virtually impossible to present a concise and simple systematization within the scope of a limited review.…”
I. Introduction 93 II. Triangulanes: Nomenclature, Classification, and Stereoisomerism 94 III. Synthesis of Triangulanes 96 A. Synthetic Methods to Assemble Oligospirocyclopropanes 96 B. Synthesis of Unbranched Triangulanes (UTs) 97 C. Synthetic Approaches to Branched Triangulanes (BTs) 99 D. Cycloannelated Triangulanes (CATs) 102 E. Along the Route to Cyclotriangulanes (CTs) 103 F. Substituted Triangulanes 104 G. Heterotriangulanes 108 IV. Selected Physical Properties of Triangulanes 109 A. Spectral Data 109 B. Bonding Properties and Molecular Structures 110 C. Thermochemical Properties 115 V. Chemical Transformations of Triangulanes 117 A. With Retention of the Skeleton 117 B. With Ring Opening 121 VI. Triangulanes with Properties of Potential Practical Applicability 130 VII. Conclusions and Further Perspectives 133 VIII. Acknowledgments 136 IX. References 136 † Dedicated to Professor Wolfgang Lu ¨ttke on the occasion of his 80th birthday.
HKoMe )CP-ClMeaSi + -f i o d e r + 0 P h C = P H' 6 M e 3 4 5 Methoxy-3-phenyl-2-phosphaazulen 5 umsetzt. 5 wird nach chromatographischer Isolierung und Reinigung in Form roter Bliittchen (Ausbeute 6%, Fp = 85-87 "C) erhalten, die sich in CHCIJ mit griiner Farbe 1 6~e n~~~. Das 'H-NMR-Spektrum von 515'] belegt die Regioselektivitiit der Cycloaddition; das Vorliegen des isomeren 1-Phosphaazulens kann ausgeschlossen werden. Die Tieffeldverschiebung der Signale der Ringprotonen 4-H und 8-H und in geringerem MaBe auch 6-H ist wie bei 1 in Ein-Hang rnit der dipolaren Struktur der Azulene. Die "P-NMR-chemische Verschiebung (CDC13/CHC13, 6= + 177.9) ist fiir dreibindigen Phosphor rnit der Koordinationszahl 2 in einem mesomeriestabilisierten System charakteristisch (S( 1) = + 168.3; S(2,4,6-Triphenyl-h3phosphorin)= + 178). Das UV-Spektrum von 5 ist rnit der Azulenstruktur ebenfalls in EinI~lang'~~], wie ein Vergleich mit den langwelligen Absorptionsmaxima von 1 -Methoxy-azulenIq und 1-Phenylazulen" zeigt. [*I Riv.-Doz. Dr. U. H. Brinker, G. Wilk, K. Gomann Abteilung f i r Chemie der Universiat UniversitatsstraDe 150, D-4630 Bochum 1 [**I Diese Arbcit wurde von der Deutschcn Fonchungsgemeinschaf?. dcm Fonds dcr Chemischcn Industrie und der Fa. Degussa (Chemikalien) UnterstOtzt. Dr. R. Sieafried danken wir mr die Hilfc bci der LOsung von HPLC-Trennproblemcn, Mv.-Doz. Dr. I f . Duddeck und M . Kaiser for NOE-Diffcrcnz-'H-NMR-Experimente und Prof. Dr. D. Hasselmann Rlr Diskussionen. 892 0 Vedag Chemie GmbH. 0-6940 Weinheim. 1983 0044-8249/83/1111-0892 S 02.SO/O Angew. Chem. 95 (1983) Nr. I1
influenced by the bridging; the conformation preferred in the crystal (see Fig. 2) is not crown-but saddle-shaped, as in 1,4,7-tro~onin['~]. Since the change in conformation in all these cases161 is not likely to require much extra energy, 3 and 4 may, like the parent system, be regarded as potential novel crown ether-like ligands for metal complexes. r 1
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.
