Benzoate linker

M. Grathwohl and R. R. Schmidt, Solid phase synthesis of oligomannosides and of a lactosamine containing milk trisaccharide using a benzoate linker, Synthesis, 15 (2001) 2263-2272. 

Scheme 9. SPOS of a(l-2)-linked mannan with the help of a benzoate linker to the primary hydroxy group of mannose.

The developed highly successful SPOS methodology based on a benzoate linker is summarized in Scheme 14. It is technically simple, thus lending itself available to automation, which was successftil with an accordingly designed... 

Scheme 14. Schematic representation of the benzoate linker SPOS.

An illustrative example of an alternative strategy (cf Fig. 11c) involving the use of a novel traceless linker is found in the multistep synthesis of 6-epi-dysidiolide (363) and several dysidiolide-derived phosphatase inhibitors by Waldmann and coworkers [153], outlined in Scheme 70. During the synthesis, the growing skeleton of 363 remained attached to a robust dienic linker. After completion of intermediate 362, the terminal olefin in 363 was liberated from the solid support by the final metathesis process with concomitant formation of a polymer-bound cyclopentene 364. Notably, during the synthesis it turned out that polymer-bound intermediate 365a, in contrast to soluble benzoate 365b, produced diene 367 only in low yield. After introduction of an additional linker (cf intermediate 366), diene 367 was released in distinctly improved yield by RCM. 

FIGURE 3.5 Fourier Transform infrared (FTIR) spectra of acrylic rubber (ACM)-siUca hybrid nanocomposites. The numbers after ACM (10 and 50) indicate the wt% tetraethoxysilane (TEOS) concentration. The letters preceding the numbers indicate the ACM-silica samples cross-linked from benzoyl peroxide (B) and a mixed cross-linker hexamethylene diamine carbamate and ammonium benzoate (D). The numbers over the absorption peaks are the wave numbers corresponding to absorbance of those peaks. (From Bandyopadhyay, A., Bhowmick, A.K., and De Sarkar, M., J. Appl. Polym. Sci., 93, 2579, 2004. Courtesy of Wiley InterScience.)... 

Weltman, J.K., Hohnson, S.-A., Langevin, J., and Riester, E.F. (1983) N-Succinimidyl(4-iodoacetyl)amino benzoate Anew heterobifunctional cross-linker. BioTech. 1, 148-152. 

The solid-phase synthesis of oligosaccharides is usually performed using acid-resistant linkers and protective groups, because of the slightly acidic reaction conditions required for glycosylations (Section 16.3). Hydroxyl group protection is conveniently achieved by conversion into carboxylic esters, such as acetates, benzoates, or nitro-benzoates. Support-bound esters of primary or secondary aliphatic alcohols can be cleaved by treatment with alcoholates [97-99] (Table 7.8), with DBU in methanol, with hydrazine in DMF [100] or dioxane [101], or with ethylenediamine [102], provided that a linker resistant towards nucleophiles has been chosen. 

In contrast, the intramolecular energy transfer in cyclooctene derivatives 63E-65E, which are tethered to benzoate, isophthalate, and terephthalate moieties through a (/ ,/ )-2,4-pentadiol linker, does not appear to be seriously affected by the steric bulk of 1-alkylation (Scheme 10) [50]. Upon irradiation at — 65°C, 63, 64, and 65 afforded ZJE ratios of 0.8,0.15, and 0.06, with diastereomeric excesses (des) of 33, 37, and 44%, respectively. 

Ant -( 1 — 3)-a-L-Rhap-( 1 —>3)-a-L-Rhap-(l —>2)-a-L-Rhap-O-linkers-BSA Glycosyl Chloride, AgOTf, DBMP thiorhamnoside, NIS, AgOTf. Benzoate, acetate, 76... 

Early reports of metalloligands include Cu complexes that contain oxamate, oxamide, benzoate, or propionate.Utilization of the metalloligand, [ Cu(2,4-pydca)2(H20) 2Et3NH] (pydca = pyridine-2,4-dicarboxylate) as a linker provides a porous coordination polymer, [ ZnCu-(2,4-pydca)2(H20)3(DMF) DMF] , where Zn ion at the node of the network acts as a connector and the Cu ions in the channel walls are available for guest coordination, as illustrated in... 

Preliminary investigations were conducted to examine the effects of imidazole on the hydrolysis of 2-methacryloyl ethyl/>-amino benzoate, 19. Polymers were formulated with an equimolar mixture of A -vinyl imidazole (NVIm), 19 and 2-hydroxyethyl methacrylate (20) using EGDMA as a cross-linker [P(20-19-NVIm)] (Scheme llA). A second polymer was formulated without 7V-vinyl imidazole [P(20-19)]. The rate constant for release of />-aminobenzoic acid from P(20-19) was 6.07 X 10 day compared to 8.07 x 10 day for P(20-19-NVIm). These experiments establish that the presence of imidazole in a network polymer with... 

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