Sulfonates modifier

The separation of the same charged compounds were also accomplished on an ethyl-pyridine bonded silica surface and 30 0% methanol/C02 mobile phases without the need of added sulfonate modifier. Anionic compounds did not elute from the ethyl-pyridinium surface that lead the authors to hypothesize that the surface was positively charged. To further test this hypothesis, the separation of the same compounds on a strong anion exchange column, silica-based propyltri-methylammonium cationic surface, which exhibits are permanent positive charge was attempted. The same retention order was observed on the strong cation exchange surface. 

As for the effect of anionic group, there are a number of reports dealing with the antithrombogenic behavior of sulfonate-modified surfaces of segmented polyurethane (SPU). An interesting feature of the adsorptive behavior of fibrinogen on these material surfaces will be discussed in Sect. 4.1. 

LSD lignin sulfonates modified by terephthaloyl chloride and subsequently by 2,4-D (22)... 

LF lignin sulfonates modified by phenol and formaldehyde and then by 2,4-D (23). 

It can be concluded that lignin sulfonates modified by reaction with herbicide functionality (21-23) can be used as potential carriers for controlled release herbicides. This application of lignin sulfonates offers several advantages both for agriculture and for the environment. 

Luo, H. et al. Application of sihca-based hyper-cross linked sulfonate-modified reversed stationary phases for separating highly hydrophihc basic compounds. J. Chromatogr. A. 2008, 1202, 8-18. 

INVESTIGATION OF HORSERADISH PEROXIDASE ADSORPTION ON GOLD AND POLYSTYRENE SULFONATE MODIFIED SURFACES BY QUARTZ CRYSTAL MICROBALANCE TECHNIQUE... 

The functionalization of an exocyclic carbon atom of the pyranose or furanose ring using vinyl sulfone-modified carbohydrate has not been explored in spite of the efficient use of vinyl sulfone-modified pyranose derivative as a Michael acceptor for the synthesis of maytansinol [1]. 

After an observation that carbon nucleophiles add to vinyl sulfone-modified hex-2-enopyranosides 35 and pent-2-enofuranosides 36 (Fig. 8.11) in a diastereo-selective fashion to the C2 carbon of the olefinic system from a direction opposite to that of the disposition of the anomeric methoxy group [8], Das et al. [9] undertook a study of the addition of carbon nucleophiles to vinyl sulfone-modified... 

The Michael-type addition reaction of carbon nucleophiles to vinyl sulfone-modified carbohydrates should be considered as an efficient route for the synthesis of branched-chain sugars because almost all carbohydrates in pyranose and furanose form could be converted to their vinyl sulfone derivatives very easily [5, 12-14]. Moreover, the product of the reaction carrying sulfone functionality has the potential to undergo a wide variety of transformations [15]. For a review on desulfonylation reaction, see Ref. [16]. 

It was reported that a nucleophile attacked the C2 position of the 2 -enesulfone nucleoside exclusively from the a-face of the pent-2 -enofuranosyl moiety of a P-nucleoside [17, 18]. This observation led to a study of the effect of the anomeric configuration on the stereochemical outcome of the addition of nucleophiles to vinyl sulfone-modified carbohydrates (Fig. 8.15). 

Das I, Pathak T (2005) A diastereoselective and general route to 5-amino-5- deoxysugars influence of C-3 substitution on the addition of amines to C-5 of vinyl sulfone-modified hex-5-enofuranosyl carbohydrates. J Org Chem 70 8047-8054... 

Ravindran B, Sakthivel K, Suresh CG, Pathak T (2000) Diastereoselective addition of amines to vinyl sulfone modified carbohydrates a highly flexible methodology for the synthesis of new classes of deoxyamino sugars. J Org Chem 65 2637-2641... 

Das I, Pal TK, Suresh CG, Pathak T (2007) Diastereoselective C-C bond formation at C-5 of vinyl sulfone-modified hex-5-enofuranosyl carbohydrates diversity-oriented synthesis of branched-chain sugars and beyond. J Org Chem 72 5523-5533... 

Sanki AK, Suresh CG, Falgune LTD, Pathak T (2003) Anomeric configuration-directed diastereoselective C-C bond formation in vinyl sulfone-modified carbohydrates a general route to branched chain-sugars. Org Lett 5 1285-1288... 

Sanki AK, Pathak T (2002) A glycosylation driven strategy for the synthesis of anomerically pure vinyl sulfone-modified pent-2-enofuranoses and hex-2-enopyranoses. Synlett 1241-1244... 

Hed Hedrick, J. L., Yilgor, I., Jurek, M., Hedrick. J. C., Wilkes, G. L., McGrath, J. E. Chemical modification of matrix resin networks with engineering thermoplastics 1. Synthesis, morphology, physical behaviour and toughening mechanisms of poly (arylene ether sulfone) modified epoxy networks. Polymer 32 (1991) 2020-2032. 

OOMar Martinez, L, Martin, M. D., Eceiza, A., Oyanguren, P., Mondragon, I. Phase separation in poly-sulfone-modified epoxy mixtures Relationships between curing conditions, morphology and ultimate behavior. Polymer 41 (2000) 1027-1035. 

The oxidative polymerization with the aid of persulfate in water is limited to EDOT and a few derivatives, which are water-soluble to a certain extent (for example, EDOT-CH3, EDOT-CH2OH, sulfonate-modified EDOT or oligo-ethylenglycol-substituted EDOT). In contrast, the in situ polymerization is of far broader range with respect to the EDOT derivatives applicable. The minimum prerequisite is a moderate to good solubility in alcohols like ethanol or n-butanol at slightly elevated or room temperature. Another important aspect is the reactivity of the monomer, which must not be too high with iron-III toluenesulfonates to avoid instantaneous polymerization. 

Jong, S.R. and Yu, TL. (1997) Physical aging of poly (ether sulfone)-modified epoxy resin. J. Polym. Sci. Polym. Phys.,... 

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