Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

Shimizu, Tomoe; Ueno, Ryuji; Ziewandy, Masa'odi; Yamato, Takehiko

doi:10.3184/030823409x401105

Cited by 4 publications

(6 citation statements)

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“…confirmed by comparing the 1 H NMR chemical shifts of aromatic, methoxy and methyl protons with those of analogues 9-methoxy[3.3]metacyclophane-2,11-diones 5a-c. [25][26][27] The IR spectra of 4b and 4c show the absorption of the carbonyl stretching vibration around 1698 and 1703 cm -1 . The 1 H NMR spectrum (CDCl 3 , 300 MHz) of 4b and 4c…”

Section: Resultsmentioning

confidence: 99%

“…[25][26][27] The coupling reaction of (p-tolylsulfonyl)methyl isocyanide (TosMIC) adducts 2 and 1-(benzyloxy)-2,4-bis(bromomethyl)-4-tert-butylbenzene 3 in the presence of NaH and followed by acid treatment afforded diketones 4a-c. In general, a mixture of 2a-c and 3 or 1c in N,N-dimethylformamide (DMF) was added dropwise to a suspension of NaH in DMF at room temperature.…”

Section: Resultsmentioning

confidence: 99%

“…at 9 or 18-position. [25][26][27] In present study, we report on the synthesis and stereochemical assignments of larger group 9-benzyloxy-18-substituted[3.3]MCP-2,11-diones and their conversion to the corresponding [3.3]MCPs by Wolff-Kishner reduction. The benzyloxy-cyclophanes would be more crowded, less flexibility and undergo anti to syn isomerisation less readily.…”

Section: Fig 1 Possible Conformers For [33]metacyclophanesmentioning

confidence: 99%

“…MCP-diones 4a-c and 5a-c were converted to corresponding MCPs by using WolffKishner reduction at high temperature 200 °C as reported procedure [25][26][27]. Conformational transformation from anti-to syn-isomer was observed for anti-4a, anti-5a and anti-5b.…”

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Synthesis and conformational studies of 9-benzyloxy-18-substituted [3.3]metacyclophanes

et al. 2015

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A series of syn- [3.3]metacyclophanes (MCPs) containing internal substituted benzyloxy group have been synthesized by the modified TosMIC coupling reaction, followed by acid treatment and Wolff-Kishner reduction. anti-Mono-and di-benzyloxy[3.3]MCPs are synthesized by Obenzylation of the corresponding hydroxy[3.3]MCPs, which are obtained by demethylation of methoxy[3.3]MCPs with BBr 3 at room temperature. An interesting and intriguing result was obtained when syn -6,15-di-tert-butyl-9-methoxy-18-methyl[3.3]MCP-2,11-dione was treated with TMSI afforded to form dihydrobenzofuran ring by nucleophilic intramolecular cyclization reaction. The 1 H NMR and X-ray analysis of 6a confirms that it adopts syn (chair-chair) conformation in both solution and solid state.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Fig 1 Possible Conformers For [33]metacyclophanesmentioning

confidence: 99%

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Synthesis and conformational studies of 9-benzyloxy-18-substituted [3.3]metacyclophanes

et al. 2015

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“…Introduction of the substituents at the 8-position increases the strain in the molecule in comparison with the unsubstituted [2.2]MPCP (1); the deformation of para-benzene ring of 8methyl[2.2]MPCP (2) was estimated to 15°by our previous X-ray crystallography. 9 Thus introduction of methyl group to the para benzene ring of [2.2]MPCP also increases the strain in the molecule.…”

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Synthesis of polymethyl substituted [2.2]metaparacyclophanes and their Lewis-acid induced isomerisation to [2.2]metacyclophanes

Shimizu

Hita

Paudel

et al. 2009

Journal of Chemical Research

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The preparation of polymethyl substituted [2.2]metaparacyclophanes using sulfur method and the X-ray structure determination of 4,5,6,8,12,13,15,16-octamethyl[2.2]metaparacyclophane are described. AlCl3-MeNO2-catalysed trans- tert-butylation of 5- tert-butyl-8,12,13,15,16-pentamethyl[2.2]metaparacyclophane in benzene led to isomerisation reaction to afford the strainless 8,12,13,14,16-pentamethyl[2.2]metacyclophane in 85% yield along with tert-butylbenzene.

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Synthesis of [m.n]Cyclophanes: Regiochemistry Transfer from Vinyl Halides to Cyclophanes via Fischer Carbene Complexes

Wang

Predeus

Wulff

2013

Chemistry A European J

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The double benzannulation of bis-carbene complexes of chromium with α,ω-diynes generates [m.n]cyclophanes in which all three rings are generated in a single reaction. This triple annulation process is very flexible allowing for the construction of symmetrical [n.n]cyclophanes and unsymmetrical [m.n]cyclophanes as well as isomers in which the two benzene rings are both meta bridged or both para bridged, and isomers that contain both meta and para bridges. The connectivity patterns of the bridges in the cyclophanes can be controlled by regioselectivity transfer from the bis-vinyl carbene complexes in which the substitution pattern of the vinyl groups in the carbene complexes dictate the connectivity pattern in the [m.n]cyclophanes. This synthesis of [n.n]cyclophanes is quite flexible with regard to ring size and can be used with tether lengths ranging from n=2 to n=16 and thus to ring sizes with up to 40 member rings. The only limitation to regioselectivity transfer from the carbene complexes to the [m.n]cyclophanes was found in the synthesis of para,para-cyclophanes with four carbon tethers for which the loss of fidelity occurred with the unexpected formation of meta,para-cyclophanes.

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Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

Cited by 4 publications

References 47 publications

Synthesis and conformational studies of 9-benzyloxy-18-substituted [3.3]metacyclophanes

Synthesis and conformational studies of 9-benzyloxy-18-substituted [3.3]metacyclophanes

Synthesis of polymethyl substituted [2.2]metaparacyclophanes and their Lewis-acid induced isomerisation to [2.2]metacyclophanes

Synthesis of [m.n]Cyclophanes: Regiochemistry Transfer from Vinyl Halides to Cyclophanes via Fischer Carbene Complexes

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