Carbenoide additionen an 1,5-cyclooctadien und cyclooctatetraen und intramolekulare reaktionen von substituierten bicyclo [6.1.0] non-4-enen

Dehmlow, Eckehard V.; Birkhahn, M.

doi:10.1016/s0040-4020(01)86139-1

Cited by 9 publications

(5 citation statements)

References 10 publications

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“…Thus, dibromocyclopropanation of 318 -Br furnished 319 -Br (14%) and 320 -Br (1.3%); dibromocyclopropanation of 319 -Br afforded 320 -Br in 7% yield . Treatment of 318 -CO 2 Me with 3 equiv of dimethyl diazomalonate did result in the formation of 320 -CO 2 Me (1% yield) . In most cases, the tetraadducts predominantly are the trans , cis,trans -configured derivatives 320 ; however, upon 4-fold cyclopropanation with the sterically less demanding methylene transfer reagent diazomethane, the cis,cis,trans tetraadduct 321 -H was formed in slightly higher yield than the trans,cis,trans isomer …”

Section: 3 Fused Systemsmentioning

confidence: 98%

“…237 Treatment of 318-CO 2 Me with 3 equiv of dimethyl diazomalonate did result in the formation of 320-CO 2 Me (1% yield). 238 In most cases, the tetraadducts predominantly are the trans,cis,trans-configured derivatives 320; however, upon 4-fold cyclopropanation with the sterically less demanding methylene transfer reagent diazomethane, the cis,cis,trans tetraadduct 321-H was formed in slightly higher yield than the trans,cis,trans isomer. 234 Little is known about chemical transformations of the substituted derivatives 320-X.…”

Section: Scheme 45mentioning

confidence: 99%

“…The second general approach to 140 and substituted derivatives thereof is by consecutive cyclopropanation of cyclooctatetraene ( 316 ). − In all cases, the products 320 and 321 of 4-fold cyclopropanation (Scheme and Table ) are formed in very low yields, if at all. The only possibility to increase these yields is to repeat the cyclopropanations on the mono-, bis-, and triscyclopropanated compounds 317 − 319 .…”

Section: 3 Fused Systemsmentioning

confidence: 99%

“…The second general approach to 140 and substituted derivatives thereof is by consecutive cyclopropanation of cyclooctatetraene (316). [234][235][236][237][238] In all cases, the products 320 and 321 of 4-fold cyclopropanation (Scheme 46 and Table 6) are formed in very low yields, if at all. The only possibility to increase these yields is to repeat the cyclopropanations on the mono-, bis-, and triscyclopropanated compounds 317-319.…”

Section: Fused Systemsmentioning

confidence: 99%

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Three-Membered-Ring-Based Molecular Architectures

2006

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Section: 3 Fused Systemsmentioning

confidence: 98%

Section: Scheme 45mentioning

confidence: 99%

Section: 3 Fused Systemsmentioning

confidence: 99%

Section: Fused Systemsmentioning

confidence: 99%

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Three-Membered-Ring-Based Molecular Architectures

2006

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“…In this context, Davies et al recently reported on the C–H functionalization of cyclocta-1,5-diene ( 1 ) using chiral Rh(II) catalysts and donor/acceptor diazoalkanes (Scheme a) . On the contrary, cyclooctatetraene ( 3 ) can only undergo cyclopropanation, yet the currently available methods are limited in scope, yield, or stereoselectivity. − Dehmlow first reported on the rhodium-catalyzed reaction of dimethyl diazomalonate with cyclooctatetraene, which gave cyclopropane product 4 in low yield (Scheme b). , Tomilov studied acceptor-only diazoalkanes in the presence of Rh(II) catalysts, which gave cyclopropane 5 in good yield, albeit with poor stereoselectivity (Scheme b) . The most recent report by Carpenter describes the rhodium-catalyzed cyclopropanation reaction of acceptor/acceptor carbenes with cyclooctatetraene in moderate yields .…”

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Photochemical Cyclopropanation of Cyclooctatetraene and (Poly-)unsaturated Carbocycles

et al. 2020

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We report on the use of visible light to conduct carbene-transfer reactions of donor/acceptor diazoalkanes with cyclooctatetraene and polyunsaturated carbocycles to give the corresponding cyclopropanes in excellent yields with excellent stereoselectivities. This photochemical protocol proved to be superior to conventional metal-catalyzed cyclopropanation reactions and now provides platform chemicals containing a cyclic conjugated all-cis triene. The cyclopropane is an important structural feature to prevent 6π electrocyclization. Instead, the triene moiety can now be selectively functionalized in cycloaddition reactions.

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Intermolecular Metal‐Catalyzed Carbenoid Cyclopropanations

2001

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The metal‐catalyzed decomposition of diazo compounds in the presence of alkenes is a well‐established reaction. Since the original Organic Reactions review on the reaction of ethyl diazoacetate with alkenes and aromatic compounds in 1970, several new developments have revolutionized this area of chemistry. Most notably, major advances have been made in catalyst design such that highly chemoselective, diastereoselective and enantioselective carbenoid transformations can now be achieved. Furthermore, it has been recognized that a wide array of carbenoid structures can be utilized in this chemistry, leading to a broad range of synthetic applications. This chapter comprises coverage of the metal‐catalyzed intermolecular cyclopropanations of diazo compounds containing at least one adjacent electron‐withdrawing group. The coverage of diazoacetate chemistry will be limited to material since 1970 because the previous Organic Reactions review covers the earlier literature. The alkene component is limited to alkenes, dienes, furans, and pyrroles because these are the systems that have resulted in the greatest developments since the 1970 review. Metal‐carbenoid intermediates derived from diazo compounds undergo a variety of useful reactions, including cyclopropanation, insertion, and ylide formation. In recent years several excellent reviews have appeared on various aspects of this chemistry. Three recent reviews have focused on asymmetric intermolecular cyclopropanations. Several books and reviews on carbenoid chemistry have major sections on intermolecular cyclopropanations. Because of the historical central prominence of carbenoids derived from diazoacetates, most reviews have tended to focus on this class of carbenoids. In this chapter, a comparison is presented of the chemical differences that exist among the major classes of carbenoids that contain adjacent electron‐withdrawing groups. The extensive nature of the topic precludes coverage of related reactions such as the metal‐catalyzed decomposition of diazoalkanes, phenyldiazoalkanes, or vinyldiazoalkanes that lack adjacent electron‐withdrawing functionality. Other cyclopropanation reactions such as the Simmons‐Smith reaction, photochemical or thermal decomposition of diazo compounds in the presence of alkenes, and cyclopropanation using stoichiometric metal carbenes are not covered.

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Carbenoide additionen an 1,5-cyclooctadien und cyclooctatetraen und intramolekulare reaktionen von substituierten bicyclo [6.1.0] non-4-enen

Cited by 9 publications

References 10 publications

Three-Membered-Ring-Based Molecular Architectures

Three-Membered-Ring-Based Molecular Architectures

Photochemical Cyclopropanation of Cyclooctatetraene and (Poly-)unsaturated Carbocycles

Intermolecular Metal‐Catalyzed Carbenoid Cyclopropanations

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