Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Synthesis unusual

R142 D. Eisenberg, R. Shenhar and M. Rabinovitz, Anions in Buckybowls , in Fragments of Fullerenes and Carbon Nanotubes Designed Synthesis, Unusual Reactions, and Coordination Chemistry, eds. M. A. Petrukhina and L. T. Scott, John Wiley Sons, Inc., Hoboken, N. J., 2012, p. 63. [Pg.30]

Petrukhina MA, Scott LT (eds) (2011) Fragments of hillerenes and earbon nanotubes designed synthesis, unusual reactions, and coordination chemistry. Wiley, Hoboken Sygula A (2011) Eur J Org Chem 1611-1625 Tsefrikas VM, Scott LT (2006) Chem Rev 106 4868-4884 Wu YT, Siegel JS (2006) Chem Rev 106 4843 867... [Pg.115]

Scott, L. T. Petrukhina M. Fragments of Fullerenes and Garbon Nanotubes Designed Synthesis, Unusual Reactions, and Goordination Ghemistry John Wiley Sons, Inc. Hoboken, NJ, 2011. [Pg.482]

Mohapatra PK, Sengupta A, Iqbal M, Huskens J, Verboom W (2013) Highly efficient diglycolamide-based task-specific ionic liquids synthesis, unusual extraction behaviour, irradiation, and fluorescence studies. Chem Eur J 19 3230-3238... [Pg.66]

Database searches can be used to find a reference to a known compound with a matching substructure. This is a particularly good technique if a portion of the molecule has an unusual structure. It may indicate a synthesis route or simply identify a likely starting material. [Pg.277]

Intramolecular 1,4-addition is useful for macrolide synthesis. An unusual molecule of punctaporonin B (272) has been synthesized by this 1,4-addition of 271(160]. Cyclization to form the seventeen-membered ring macrolide 273 was carried out at 0.1-0.5 vi concentration[161. The choice of ligands seems to be important in the macrocyclization. The 26-membered ring model 274 for a synthesis of the ring system of tetrin A was obtained in 92% yield by using triisopropyl phosphite as a ligand[162]. [Pg.326]

The reaction is used for the chain extension of aldoses in the synthesis of new or unusual sugars In this case the starting material l arabinose is an abundant natural product and possesses the correct configurations at its three chirality centers for elaboration to the relatively rare l enantiomers of glucose and mannose After cyanohydrin formation the cyano groups are converted to aldehyde functions by hydrogenation m aqueous solution Under these conditions —C=N is reduced to —CH=NH and hydrolyzes rapidly to —CH=0 Use of a poisoned palladium on barium sulfate catalyst prevents further reduction to the alditols... [Pg.1056]

Aldolases cataly2e the asymmetric condensation of intermediates common in sugar metaboHsm, such as phosphoenolpymvic acid, with suitable aldehyde acceptors. Numerous aldolases derived from plants or animals (Class I aldolases) or from bacteria (Class II) have been examined for appHcations (81). Efforts to extend the appHcations of these en2ymes to the synthesis of unusual sugars have been described (2,81). [Pg.312]

An unusual final example of a synthesis from pyridines involves the 4-lithiotetra-chloropyridine (128), which with two moles of benzonitrile gave the trichlorodiphenyl-pyrido[3,4- f]pyrimidine (130) via the intermediate (129) (72JCS(P1)2190). The 2-lithio analogue gave the corresponding [3,2-c] derivative. [Pg.217]

A -Amino- and A-substituted amino-pyrroles readily undergo Diels-Alder additions and add to activated alkynes at room temperature. The resulting azanorbornadienes extrude A-aminonitrenes and this forms the basis of an unusual synthesis of benzene derivatives (81S753,81TL3347). It has been found that ethyl/3-phenylsulfonylpropiolate (135) is a superior dienophile to DMAD (Scheme 50). [Pg.66]

An unusual case of addition of a carbanion to an unconjugated carbon-carbon double bond is shown in Scheme 47a. The subsequent transfer of the amide group is also noteworthy (80CC1042). The intramolecular addition of a carbanion to an aryne is a more widely established process. Such reactions have been applied to the synthesis of indoles (Scheme 47b) (75CC745> and oxindoles (Scheme 47c) (63JOC1,80JA3646). [Pg.115]

Clavulones I and II are members of an unusual family of marine prostanoids from the coral Clavularia viridis which are biosynthesiied by a cationic (i.e. non-radical, non-endoperoxide) pathway. The total synthesis of clavulones I and II was accomplished from cyclopentadiene as SM goal. [Pg.303]

Graphite was tised as substrate for the deposition of carbon vapor. Prior to the tube and cone studies, this substrate was studied by us carefully by STM because it may exhibit anomalotis behavior w ith unusual periodic surface structures[9,10]. In particular, the cluster-substrate interaction w as investigated IJ. At low submonolayer coverages, small clusters and islands are observed. These tend to have linear struc-tures[12j. Much higher coverages are required for the synthesis of nanotubes and nanocones. In addition, the carbon vapor has to be very hot, typically >3000°C. We note that the production of nanotubes by arc discharge occurs also at an intense heat (of the plasma in the arc) of >3000°C. [Pg.65]

The true, all-aromatic system (see 18, below) described by Kime and Norymberski is unusual in the sense that all of the ether linkages bridge aromatic carbons ". Synthesis of 18, therefore, required extensive use of copper mediated coupling reactions. As expected for such reactions, yields were generally low. The aromatics such as 18 were ineffective at binding either alkali metal or ammonium cations ". ... [Pg.44]

An unusual and different use of an aryldifluorovinyllithium compound is the synthesis of acetylenic compounds containing no fluorine [65] (equation 32)... [Pg.662]


See other pages where Synthesis unusual is mentioned: [Pg.137]    [Pg.242]    [Pg.137]    [Pg.242]    [Pg.119]    [Pg.260]    [Pg.262]    [Pg.227]    [Pg.507]    [Pg.190]    [Pg.524]    [Pg.411]    [Pg.163]    [Pg.424]    [Pg.329]    [Pg.88]    [Pg.65]    [Pg.178]    [Pg.565]    [Pg.52]    [Pg.139]    [Pg.253]    [Pg.259]    [Pg.297]    [Pg.225]    [Pg.425]    [Pg.7]    [Pg.30]    [Pg.228]    [Pg.569]    [Pg.305]    [Pg.941]    [Pg.53]   
See also in sourсe #XX -- [ Pg.11 ]




SEARCH



A Most Unusual Synthesis of Tropones from Phenols

A Novel Synthesis of Vinyl Ethers via an Unusual Exchange Reaction

An Unusual - but Inefficient - Synthesis of Methyl

© 2024 chempedia.info