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Solid-phase/fluorous synthesis

In 2004, Kumar and Montanari introduced a fluorous tagged trivalent iodonium compound that can be used as a tag for /-Boc based solid phase peptide synthesis by tagging free amines with a perfluoroheptyl (W-C7F15) group.It is an efficient fluorous tagging reagent that has the potential to help in the synthesis of both routine and difficult peptide and protein sequences. The... [Pg.164]

Fluorous reverse phase silica gel (FRPSG) has been used in the purification of synthetic DNA fragments.In solid phase DNA synthesis, truncated sequences are often separated from the desired product after deprotection using HPLC or electrophoresis. In order to perform, parallel syntheses and separations of nucleotides the trityl-on purification procedure was developed, in which a lipophilic support material is used to separate the desired and undesired product, followed by deprotection. If the protecting group is labelled with a fluorous group, fiuorous-fiuorous interactions between the FRPSG and the protected nucleotide can be used to aid separation of the aqueous mixture. [Pg.165]

Montanari, V. and Kumar, K. (2006) A fluorous capping strategy for Fmoc-based automated and manual solid-phase peptide synthesis. European Journal of Organic Chemistry, (4), 874-877. [Pg.439]

In the last few years fluorous combinatorial chemistry has been extended and augmented by other fluorous techniques developed by analogy with established methods in solid-phase-supported synthesis. Use of fluorous condensation reagents for the Mitsunobu reaction [23] enables easy removal of all condensation reagents except the coupled starting materials after the reaction [24] (Scheme 3.23). A fluorous variant of the Swern [25] and Corey-Kim oxidations [26] enables handling of stoichiometric quantities of malodorous dimethyl sulfide to be avoided [27] (Scheme 3.24). [Pg.198]

Zhang Q, Luo Z, Curran DP (2000) Separation of Light Fluorous reagents and catdysts by fluorous solid-phase extraction synthesis and study of a femily of Triarylphosphines bearing linear and branched fluorous tags. J Org Chem 65 8866-8873... [Pg.262]

Microwave and fluorous technologies have been combined in the solution phase parallel synthesis of 3-aminoimidazo[l,2-a]pyridines and -pyrazines [63]. The three-component condensation of a perfluorooctane-sulfonyl (Rfs = CgFiy) substituted benzaldehyde by microwave irradiation in a single-mode instrument at 150 °C for 10 min in CH2CI2 - MeOH in the presence of Sc(OTf)3 gave the imidazo-annulated heterocycles that could be purified by fluorous solid phase extraction (Scheme 9). Subsequent Pd-catalyzed cross-coupling reactions of the fluorous sulfonates with arylboronic acids or thiols gave biaryls or aryl sulfides, respectively, albeit it in relatively low yields. [Pg.40]

Abstract Current microwave-assisted protocols for reaction on solid-phase and soluble supports are critically reviewed. The compatibility of commercially available polymer supports with the relatively harsh conditions of microwave heating and the possibilities for reaction monitoring are discussed. Instrmnentation available for microwave-assisted solid-phase chemistry is presented. This review also summarizes the recent applications of controlled microwave heating to sohd-phase and SPOT-chemistry, as well as to synthesis on soluble polymers, fluorous phases and functional ionic liquid supports. The presented examples indicate that the combination of microwave dielectric heating with solid- or soluble-polymer supported chemistry techniques provides significant enhancements both at the level of reaction rate and ease of purification compared to conventional procedures. [Pg.80]

In a related approach from the same laboratory, the perfluorooctylsulfonyl tag was employed in a traceless strategy for the deoxygenation of phenols (Scheme 7.82) [94], These reactions were carried out in a toluene/acetone/water (4 4 1) solvent mixture, utilizing 5 equivalents of formic acid and potassium carbonate/[l,T-bis(diphe-nylphosphino)ferrocene]dichloropalladium(II) [Pd(dppf)Cl2] as the catalytic system. After 20 min of irradiation, the reaction mixture was subjected to fluorous solid-phase extraction (F-S PE) to afford the desired products in high yields. This new traceless fluorous tag has also been employed in the synthesis of pyrimidines and hydantoins. [Pg.352]

Furthermore, multicomponent reactions can also be performed under fluorous-phase conditions, as shown for the Ugi four-component reaction [96], To improve the efficiency of a recently reported Ugi/de-Boc/cyclization strategy, Zhang and Tempest introduced a fluorous Boc group for amine protection and carried out the Ugi multicomponent condensation under microwave irradiation (Scheme 7.84). The desired fluorous condensation products were easily separated by fluorous solid-phase extraction (F-SPE) and deprotected by treatment with trifluoroacetic acid/tet-rahydrofuran under microwave irradiation. The resulting quinoxalinones were purified by a second F-SPE to furnish the products in excellent purity. This methodology was also applied in a benzimidazole synthesis, employing benzoic acid as a substrate. [Pg.353]

Fluorous ligands introduce an ease of purification in that the tagged phosphine ligand, the palladium catalyst complexed ligand, and the oxidized ligand can be completely removed by direct fluorous solid-phase separation (F-SPE) prior to product isolation. Similarly, an example of a fluorous palladium-catalyzed microwave-induced synthesis of aryl sulfides has been reported, whereby the product purification was aided by fluorous solid-phase extraction [91]. [Pg.355]

Curran DP, Luo ZY (1999) Fluorous Synthesis with Fewer Fluorines (Light Flu-orous Synthesis) Separation of Tagged from Untagged Products by Solid-Phase Extraction with Fluorous Reverse-Phase Silica Gel. J Am Chem Soc 121 9069-9072... [Pg.17]

By analogy to the usual usage of solid phase synthesis , we intend "fluorous synthesis to mean techniques in which the substrate or product is fluorous. However, the term fluorous synthesis is also sometimes used more broadly to encompass essentially any fluorous technique... [Pg.37]

A. Studer, D. P. Curran, A Strategic Alternative to Solid Phase Synthesis Preparation of A Small Isocazoline Library by Fluorous Synthesis , Tetrahedron 1997, 53, 6681... [Pg.37]

In addition, a novel fluorous support has been developed recently as an alternative to traditional polymer supports and applied successfully to oligosaccharide synthesis in combination with the trichloroacetimidate method [541]. Each intermediate in the fluorous oligosaccharide synthesis [542,543] could be obtained by simple fluorous-organic solvent extraction, and the reactions could be monitored by TLC, NMR and MS, in contrast to solid-phase reactions. Moreover, the new liquid-phase technique is anticipated to be easily applicable to the large-scale synthesis. [Pg.193]

Another elegant technique in fluorous synthesis is the use of reverse-phase fluorinated silica gel as a solid separation phase. Such fluorinated solids allow the separation of fluorous from nonfluorous materials by selective adsorption, and can even be used for chromatographic separations by degree of fluorination (Kainz et al., 1998). These techniques require a considerably lower content of fluorine for efficient separation and have been referred to as light fluorous synthesis (Curran and Luo, 1999). [Pg.86]

Apart from its use for solvation and separation of catalysts, the fluorous phase can also be used advantageously for separation processes during workup. Strategic synthesis planning is facilitated by tagging with fluorous residues to overcome the frequently limiting recovery and purification difficulties [1], As in solid-phase syntheses, an excess of components can be used to drive the reactions to completion. Side products can easily be separated if, for example, only the product is tagged with fluorous alkyl residues and therefore precipitates from the reaction mixture or is extracted with the fluorous phase. [Pg.97]

In fluorous synthesis, the possibility for separation on a fluorous solid phase allows for reduction of the fluorine content in the tags. Fluorous resins offer a way to confront the high molecular weight problem resulting from fluorous tagging and therefore the problem of atom economy in fluorous-phase chemistry. [Pg.102]


See other pages where Solid-phase/fluorous synthesis is mentioned: [Pg.406]    [Pg.5]    [Pg.166]    [Pg.164]    [Pg.413]    [Pg.283]    [Pg.248]    [Pg.229]    [Pg.292]    [Pg.72]    [Pg.112]    [Pg.114]    [Pg.123]    [Pg.181]    [Pg.73]    [Pg.292]    [Pg.348]    [Pg.350]    [Pg.354]    [Pg.1]    [Pg.27]    [Pg.32]    [Pg.32]    [Pg.33]    [Pg.35]    [Pg.178]    [Pg.367]    [Pg.101]    [Pg.120]    [Pg.52]   


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