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Solid-phase Synthesis and Self-assembly Formation of Tyrocidines

Ding Y., Qin C. G., Niu W. N., Li Y., Zhang R. J.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 9

1577-1585

EN

A facile and efficient method was applied for parallel total synthesis of natural cyclic decapeptides, tyrocidine A-E, on safty-catch resin. Synthetic products were equally active as the natural products isolated from the bacterial source and found to possess similar bacterial selectivity as other members in the amphipathic antimicrobial cyclic decapeptide family. At the same time, the self-assembling nanotubes of them were observed under a transmission electronic microscopy.

2

Narzędzia chemii kombinatorycznej. Cz. 4. Synteza asymetryczna na fazie stałej

Łaźny R., Nodzewska A., Żabicka B.

Wiadomości Chemiczne

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2006

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[Z] 60, 3-4

191-255

EN

Solid Phase Asymmetric Synthesis (SPOS) is a recently introduced term embracing all methods of asymmetric synthesis involving use of solid supported substrates and reagents. This review presents basic definitions of asymmetric synthesis and currently used concepts for enatioselective and diastereoselective transformations involving supported synthesis. The concepts of chiral auxiliary, chiral catalyst and chiral reagent are illustrated with selected but fairly comprehensive overview of methods published till January 2005. In particular use of chiral auxiliaries such as oxazolidine derivatives, amines, hydrazines, sulfoxides, sulfinyl amides, sulfoxy imines, carbohydrates and alcohols is covered. Applications of immobilized chiral catalysts to synthesis of carbon-carbon bonds, carbon-hydrogen bonds, carbon--heteroatom bonds and in phase-transfer catalysis is presented with selected reactions due to huge volume of literature in this field. Moreover applications of chiral catalysts and chiral reagents in reactions of immobilized substrates and use of chiral immobilized reagents is also reviewed. The literature review shows that the most popular methods of supported asymmetric synthesis are the alkylation of enolates, aldol reactions, Grignard reactions, cycloadditions, reduetion of ketones, epoxida-tions, olefin dihydroxylation, and phase-transfer catalyzed reactions. There are numerous applications of immobilized chiral catalysts and a substantial number of applications of immobilized chiral auxiliaries. On the other hand there are only scarce reports of applications of chiral reagents and chiral catalysts to the reactions of achiral immobilized substrates.

3

Narzędzia chemii kombinatorycznej. Cz 3. Reakcje w syntezie organicznej na fazie stałej

Łaźny R., Łapińska M., Sienkiewicz M.

Wiadomości Chemiczne

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2005

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[Z] 59, 11-12

881--952

EN

Solid Phase Organic Synthesis (SPOS) is a dynamically growing branch of organic synthesis encompusing methods for synthesis of both small molecules and oligomers on solid supports. Synthetically useful organic reactions of substrates immobilized on solid supports constitute a central part of the methodology of solid phase synthesis. This review article presents a representative and fairly comprehensive overview of reactions of supported substrates published till January 2005. The reactions are classified in synthetic terms into functional group interconvertions (FG1, according to type of functional group reacting and prepared) and C-C bond forming reactions (according to reaction type; usually name reaction). Fn particular preparations of halogens, alcohols, ethers, thiols, aldehydes, ketones, acids, esters, amides, phosphines, amines, poliamines, peptides, peptoids, oligonucleotides, and oligosaccharides is covered. Oxidation reactions of alcohols, aldehydes and ketones as well as reduction reactions of aldehydes, ketones, esters, acids, nitro and nitroso compounds are also presented. Only the selected reactions used for preparation of oligonucleotides, oligosaccharides, and polypeptides are covered due to the large volume of literaturę on this topie. The important C-C bond forming reactions such as Mannich, Michael, aldol, Heck, Suzuki, Stille, Sonogashira, Wittig, Horner-Wad-sworth-Emmons, metathesis, carbonyl compound alkylation and acylation reactions are illustrated with examples. Moreover the multicomponent reactions such as Ugi reaction, Hantzsch reaction and Baylis-Hillman reaction are also included in the review. The literature review shows a spectrum of synthetic organic reactions which can be performed on the immobilized substrates and suggests that in principle every reaction could be performed on solid phase. Howeverthe literature review indicates that reactions of polar organometallic reagents, radical reactions, and enantioselective reactions of achiral immobilized substrates are rather rarely used in SPOS.

4

A Purification Strategy for Oligosaccharide Synthesis on Soluble Polymer Supports

Ojeda R., Martin-Lomas M.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 2

309-315

EN

Removal of deficient sequences in the synthesis of oligosaccharides on soluble polymer supports can be efficiently achieved by selective esterification of the soluble supportbound incomplete glycosylation products with a conveniently functionalized insoluble resin.

5

A Facile Synthesis of the Fucosylated N-Linked Glycan Core and Its Application to Solid-Phase Synthesis of CD52 Glycopeptide

Shao N., Guo Z.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 2

297-307

EN

An efficient synthesis of the fucosylated N-linked core hexasaccharide (23) and its asparagine conjugate (26), as well as their applications to the solid-phase synthesis of an extensively protected glycopeptide (1) of CD52 antigen containing the hexasaccharide, is described. The difficult beta-mannosidic and alfa-fucosidic linkages were achieved by the Crich and in situ anomerization protocols respectively, which offered excellent results. An especially acid-sensitive resin, 2-chlorotrityl resin, was used in the solid-phase synthesis, and the target glycopeptide 1 could be released from the resin by 10% HOAc without affecting the acid-labile protecting groups and fucosidic bond.

6

Narzędzia chemii kombinatorycznej. Cz.2. Łączniki stosowane w syntezie organicznej na fazie stałej

Łaźny R., Michalak M.

Wiadomości Chemiczne

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2003

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[Z] 57, 11-12

1061--1091

EN

Linkers constitute fundamental tools of polymer supported synthesis and combinatorial chemistry. Synthesis of any compound on solid support requires an efficient method for binding substrate molecules to solid phase and methods for cleavage of product molecules from the support after completion of the synthetic sequence. This review article presents role of linkers in solid-phase synthesis, analogy between linkers and protecting groups, and properties of linkers that need to be considered when planning synthesis of a particular compound on solid support. Basic concepts of linker methodology are presented and illustrated with selected examples. In addition the role of the linker as protection or activation of functional group of the substrate and an element controlling regio- or chemoselectivity is mentioned. The selected, representative examples of classical and recently elaborated linkers are classified according to the condition of cleavage. These include acid sensitive, base or nucleophile sensitive, photolabile, safety catch linkers, traceless linkers and cyclative cleavage linkers.