2,6,9-Trioxabicyclo[3.3.1]nona-3,7-dien-4-oyl and tetraoxaadamantan-9-oyl functionalized aromatic di- and triamines: synthesis, stereochemistry and complexation

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Section: Methodssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Synthesis of functionalized macrocyclic derivatives of trioxabicyclo[3.3.0]nonadiene

Leber

Kollenz

Wentrup³

2012

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“…Preparations of the di(hexylurea) 4 , the di(ethyl urethane) 5 and the diamides 7 were carried out as previously described [ 1 , 11 – 13 ].…”

Section: Methodsmentioning

confidence: 99%

Molecular cleft or tweezer compounds derived from trioxabicyclo[3.3.1]nonadiene diisocyanate and diacid dichloride

Kollenz¹,

Smounig²,

Belaj³

et al. 2015

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SummaryThe structures of two derivatives of the bisdioxine diisocyanate 1, the bisurea 4 and the biscarbamate 5, are established by X-ray crystallography and DFT calculations. These compounds possess endo,endo structures, in the case of the bisurea 4 with two nearly parallel pendant chains. The X-ray structures are reproduced very well by DFT calculations. Similar endo,endo conformations are calculated for the bisamide crown ether derivatives 7, where two proximate and nearly parallel crown ether units endow the molecules with a claw-like molecular cleft or tweezer structure as evidenced by an enhanced ability to extract some alkali, alkaline earth and rare earth metal ions.

“…For example, compound 30 ( Fig. 1 ) was found to have a particular affinity for complexation with choline [ 26 , 36 ], and the crown-5 derivative 31 showed an enhanced ability to extract Na + and K + ions from water into CHCl 3 (22 and 21%, respectively, within 10 minutes using equimolar amounts of salt and ligand) [ 37 ].…”

Section: Reviewmentioning

confidence: 99%

From dipivaloylketene to tetraoxaadamantanes

Kollenz

Wentrup

2018

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Dipivaloylketene (2) is obtained by flash vacuum pyrolysis of furan-2,3-dione 6 and dimerizes to 1,3-dioxin-4-one 3, which is a stable but reactive ketene. The transannular addition and rearrangement of enols formed by the addition of nucleophiles to the ketene function in 3 generates axially chiral 2,6,9-trioxabicyclo[3.3.1]nonadienes (bisdioxines) 4. When arylamines are used as the nucleophiles under neutral conditions, decarboxylation occurs during the formation of bisdioxines 8. However, when water or alcohols are added to 3 under acidic conditions, bisdioxine-carboxylic acids and esters 10 and 11 are obtained. Acid hydrolysis of the bisdioxines proceeds through the addition of water to a C=C double bond and results in a second transannular oxa-Michael-type reaction and generation of tetraoxaadamantanes 5. This reaction is decarboxylative when free carboxylic acid functions are present in the bisdioxines, thus forming 21 and 22, but carboxylic acid derivatives are preserved to yield compounds 20, 23, 25, 28, and 29. A hydrogenolysis of the dibenzyl ester 23 yields the free dicarboxylic acid 24. The tetraoxaadamantanes are formed in high yields (65–95%) in most cases, but the addition of water to the concave inside of the bisdioxines becomes severely hindered in cyclic derivatives, so that the 38-membered ring compound 32 requires microwave heating at 170 °C to form tetraoxaadamantane 33, and the catenated compound 36 and calix[6]arene derivative 37 did not form tetraoxaadamantanes. The reaction mechanisms of bisdioxine and tetraoxaadamantane formation are discussed.