Carbon syntheses with -

Figure 23.14 Capacitance values in aqueous ( ) and organic (A) media of the nanotex-tured carbons synthesized with different carbon precursors and templates vs their micropore volume determined by COj adsorption. (Adapted from Ref. [90]).

Fig. 14. Capacitance values in aqueous and organic medium of the nanotextured carbons synthesized with different carbon precursore and templates vs their micropore volume determined by CO2 adsorption [6. Reprinted with permission from C. Vix-Guterl, E. Frackowiak, K. Jurewicz, M. Friebe, J. Parmentier and F. Bdguin, Carbon, 43 (2005) 1293.

Figure 2.15 General concept of the syntheses of mesoporous materials (a) mesoporous silica synthesis with soft template (b) mesoporous carbon synthesis with hard template.

Carboxyl and nitrile groups are usually introduced in synthesis with commercial carboxylic acid derivatives, nitriles, or cyanide anion. Carbanions can be carboxylated with carbon dioxide (H.F. Ebel, 1970) or dialkyl carbonate (J. Schmidlin, 1957). 

Hydroxylysine (328) was synthesized by chemoselective reaction of (Z)-4-acet-oxy-2-butenyl methyl carbonate (325) with two different nucleophiles first with At,(9-Boc-protected hydroxylamine (326) under neutral conditions and then with methyl (diphenylmethyleneamino)acetate (327) in the presence of BSA[202]. The primary allylic amine 331 is prepared by the highly selective monoallylation of 4,4 -dimethoxybenzhydrylamine (329). Deprotection of the allylated secondary amine 330 with 80% formic acid affords the primary ally-lamine 331. The reaction was applied to the total synthesis of gabaculine 332(203]. 

The reaction has been applied successfully to the synthesis of a precursor of provitamin D. 520, which has a homoannular conjugated diene in the B ring[340]. Treatment of the 7a-carbonate 518 with Pd cataJy.st at 40 C afforded the 5.7-diene 520 regioselcctively in good yield. No heteroannular diene 521... 

B. Cormels, in J. Ealbe, ed., Neir Synthesis with Carbon Monoxide, Springer-Vedag, New York, 1980, p. 1—225. 

Many nitroimidazoles possess antiprotozoal activity. One of these is bamnidazole (29). Synthesis involves reaction of imidazole carbonate 28 with ammonia. 

When 2-lithio-2-(trimethylsilyl)-l,3-dithiane,9 formed by deprotonation of 9 with an alkyllithium base, is combined with iodide 8, the desired carbon-carbon bond forming reaction takes place smoothly and gives intermediate 7 in 70-80% yield (Scheme 2). Treatment of 7 with lithium diisopropylamide (LDA) results in the formation of a lactam enolate which is subsequently employed in an intermolecular aldol condensation with acetaldehyde (6). The union of intermediates 6 and 7 in this manner provides a 1 1 mixture of diastereomeric trans aldol adducts 16 and 17, epimeric at C-8, in 97 % total yield. Although stereochemical assignments could be made for both aldol isomers, the development of an alternative, more stereoselective route for the synthesis of the desired aldol adduct (16) was pursued. Thus, enolization of /Mactam 7 with LDA, as before, followed by acylation of the lactam enolate carbon atom with A-acetylimidazole, provides intermediate 18 in 82% yield. Alternatively, intermediate 18 could be prepared in 88% yield, through oxidation of the 1 1 mixture of diastereomeric aldol adducts 16 and 17 with trifluoroacetic anhydride (TFAA) in... 

CF) is prepared by the reaction of carbon powder with fluorine gas at an elevated temperature. The properties of (CF) are similar to those of polytetrafluoroeth-ylene (PTFE) which is prepared by organic synthesis. 

Oxo esters are accessible via the diastereoselective 1,4-addition of chiral lithium enamine 11 as Michael donor. The terr-butyl ester of L-valine reacts with a / -oxo ester to form a chiral enamine which on deprotonation with lithium diisopropylamide results in the highly chelated enolate 11. Subsequent 1,4-addition to 2-(arylmethylene) or 2-alkylidene-l,3-propanedioates at — 78 °C, followed by removal of the auxiliary by hydrolysis and decarboxylation of the Michael adducts, affords optically active -substituted <5-oxo esters232 (for a related synthesis of 1,5-diesters, see Section 1.5.2.4.2.2.1.). In the same manner, <5-oxo esters with contiguous quaternary and tertiary carbon centers with virtually complete induced (> 99%) and excellent simple diastereoselectivities (d.r. 93 7 to 99.5 0.5) may be obtained 233 234. 

The methanation of synthesis gas occurs by Reactions 1 and 2 in the absence of carbon formation. With the given hydrogen carbon monoxide... 

Erdemir, A., EryUmaz, O. L., and Fenske, G., Synthesis of Diamond-like Carbon Films with Superlow Friction and Wear Properties,"/. Vac. Sci. Technol. A, Vol. 18, 2000, pp. 1987-1992. 

Both H and R can attack a ketone or aldehyde to give an alcohol. The main difference is the effect on the carbon skeleton. With H, the carbon skeleton does not change at all. But with R, the carbon skeleton gets larger. We are forming a C—C bond. We will soon see that this is very important for synthesis problems. For now, let s focus on how we can make R in the first place. After all, a negative charge on a carbon atom is not very stable (and therefore not trivial to make). 

Synthesis of polycarbonates from glycidyl methacrylate and carbon dioxide with different... 

Haruki, E. In Organic and Bioorganic Chemistry of Carbon dioxide. Organic Synthesis with Carbon Dioxide Inoue, S. Yamazaki, N. (Eds) Raised New York 1982, pp. 5-78. 

Transketolase (TKase) [EC 2.2.1.1] essentially catalyzes the transfer of C-2 unit from D-xylulose-5-phosphate to ribose-5-phosphate to give D-sedoheptulose-7-phosphate, via a thiazolium intermediate as shown in Fig. 16. An important discovery was that hydroxypyruvate works as the donor substrate and the reaction proceeds irreversibly via a loss of carbon dioxide (Fig. 17). In this chapter, we put emphasis on the synthesis with hydroxypyruvate, as it is the typical TPP-mediated decarboxylation reaction of a-keto acid. ... 

It is well known that the stable crystalline form of carbon at ambient conditions is graphite, which is fully sp hybidized. The synthesis of the fully sp -hybridized crystalline diamond is performed at high temperatures and pressures. So, the production of metastable carbon solids with a high fraction of sp -hybridized... 

The first synthesis of derivatives (77) of pentatetraene-carboxylic acid has been reported using a Wittig reaction of 1-H-allene-l,3-dicarboxylate monoester chlorides (76) in the presence of triethylamine.60 In one case an intermediate was obtained and was converted to (77) by further treatment with base. The reaction of carbon suboxide with phosphonium ylides has also... 

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