Cyclodextrins synthesis

Organosilica Mesoporous Materials with Double Functionality Amino Groups and p-Cyclodextrin Synthesis and Properties... 

Figure 16.5 P-Cyclodextrin synthesis using toluene as complexing agent.

A. Jabbari and H. Sadeghian, Amphiphilic cyclodextrins, synthesis, utilities and application of molecular modeling in their design, InTechOpen, 2012. 

Tang W, Ng SC. Monosubstituted positively charged cyclodextrins synthesis and applications in chiral separation. J. Sep. Sci. 2008 31 3246 3256. 

Resorcinol carboxylation with carbon dioxide leads to a mixture of 2,4-dihydroxyben2oic acid [89-86-1] (26) and 2,6-dihydroxyben2oic acid [303-07-1] (27) (116). The condensation of resorcinol with chloroform under basic conditions, in the presence of cyclodextrins, leads exclusively to 2,4-dihydroxyben2aldehyde [95-01-2] (28) (117). Finally, the synthesis of l,3-bis(2-hydroxyethoxy)ben2ene [102-40-9] (29) has been described with ethylene glycol carbonate in basic medium (118), in the presence of phosphines (119). Ethylene oxide, instead of ethyl glycol carbonate, can also be used (120). 

Inspired by the separation ability of cyclic selectors such as cyclodextrins and crown ethers, Malouk s group studied the synthesis of chiral cyclophanes and their intercalation by cation exchange into a lamellar solid acid, a-zirconium phosphate aiming at the preparation of separation media based on solid inorganic-organic conjugates for simple single-plate batch enantioseparations [77-80]. 

Cycloalkenyl sulphones, reactions of 646 Cycloalkyl aryl sulphones, lithiated 641 Cyclodextrins 59, 72 in asymmetric synthesis of sulphoxides 292... 

Template effects have been used in rotaxane synthesis to direct threading of the axle through the wheel. Since macrocycHc compounds such as cyclodextrins, crown ethers, cyclophanes, and cucurbiturils form stable complexes with specific guest molecules, they have been widely used in the templated synthesis of rotax-anes as ring (wheel) components. Here, we briefly discuss macrocycles used in the synthesis of rotaxane dendrimers and their important features. 

Mikolajczyk and coworkers have summarized other methods which lead to the desired sulfmate esters These are asymmetric oxidation of sulfenamides, kinetic resolution of racemic sulfmates in transesterification with chiral alcohols, kinetic resolution of racemic sulfinates upon treatment with chiral Grignard reagents, optical resolution via cyclodextrin complexes, and esterification of sulfinyl chlorides with chiral alcohols in the presence of optically active amines. None of these methods is very satisfactory since the esters produced are of low enantiomeric purity. However, the reaction of dialkyl sulfites (33) with t-butylmagnesium chloride in the presence of quinine gave the corresponding methyl, ethyl, n-propyl, isopropyl and n-butyl 2,2-dimethylpropane-l-yl sulfinates (34) of 43 to 73% enantiomeric purity in 50 to 84% yield. This made available sulfinate esters for the synthesis of t-butyl sulfoxides (35). 

Tabushi et al. (1979) have shown that p-cyclodextrin in aqueous alkaline solution allows highly selective one-step synthesis of vitamin Kj (or K2) analogues here the key step is alkylation of 2-methyl hydronaphthoquinone with allyl, crotyl, methallyl, or prenyl bromide. 

Trotta F, Martina K, Robaldo B, Barge A, Cravotto G (2007) Recent advances in the synthesis of cyclodextrin derivatives under microwaves and power ultrasound. J Incl Phenom Macro Chem 57 3-7... 

Figure 4.15 Selective adsorption synthesis of a-cyclodextrin from starch applying a hatch process using a sequence of stirred-tank reactor, heat exchanger modules and adsorption step...

D. A. Fulton and J. F. Stoddart, An efficient synthesis of cyclodextrin-based carbohydrate cluster compounds, Org. Lett., 2 (2000) 1113-1116. 

T. Furiuke, R. Sadamoto, K. Niikura, K. Monde, N. Sakairi, and S.-I. Nishimura, Chemical and enzymatic synthesis of glycocluster having seven sialyl lewis X arrays using /i-cyclodextrin as a key scaffold material, Tetrahedron, 61 (2005) 1737-1742. 

J. J. Garcia-Lopez, F. Santoyo-Gonzalez, A. Vargas-Berenguel, and J. J. Gimenez-Martinez, Synthesis of cluster V-glycosides based on a /1-cyclodextrin core, Chem. Eur. J., 5 (1999) 1775-1784. 

R. Roy, F. Hemandez-Mateo, and F. Santoyo-Gonzalez, Synthesis of persialy-lated /i-cyclodextrins, J. Org. Chem., 65 (2000) 8743-8746. 

T. Furuike, S. Aiba, and S.-I. Nishimura, A highly practical synthesis of cyclodextrin-based glycoclusters having enhanced affinity with lectins, Tetrahedron, 56 (2000) 9909-9915. 

The hydrolysis of esters by the nickel derivative (271) provided an early example of the use of a metal-capped cyclodextrin as a catalyst (shown here as its p-nitrophenyl acetate inclusion complex) (Breslow Overman, 1970 Breslow, 1971). The synthesis of this host involves the following steps (i) covalent binding of the pyridine dicarboxylic acid moiety to cyclodextrin, (ii) coordination of Ni(n) to this species, and (iii)... 

Ring-opening with heteroatomic nucleophiles is certainly among the most thoroughly studied behavior of epoxides, and this reaction continues to be a versatile workhorse of synthetic utility. This is exemplified in the recent literature by the examples of the p-cyclodextrin-catalyzed aminolysis of simple epoxides by aniline derivatives (i.e., 53 - 54) <00SL339> and the synthesis of oxa-azacrown ethers through the treatment of Ws-epoxides 55 with diamines 56. Yields in the latter synthesis are sensitive to the size of the macrocycle and substitution on the bis-epoxide <00TL1019>. 

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