2,3- benzaldehyde libraries from

As second example for the scale-up of solid-phase reactions directly on solid support, we chose an arylsulfonamido-substituted hydroxamic acid derivative stemming from the matrix metalloproteinase inhibitor library (MMP) of our research colleagues (Breitenstein et al. 2001). In this case, there was already a solution-phase synthesis available for comparison (see Scheme 4). The synthesis starts with the inline formation of a benzaldehyde 18 with the glycine methyl ester, which is then reduced to the benzylamine 20 using sodium borohydride in methanol/ THF (2 1). The sulfonamide formation is carried out in dioxane/H20 (2 1) with triethylamine as the base and after neutralisation and evaporation the product 21 can be crystallised from tert. butylmethyl ether. After deprotection with LiOH, the acid is activated by treatment with oxalyl chloride and finally converted into the hyroxamic acid 23 in 33.7% yield overall. 

The dynamic cyanohydrin libraries were generated from equimolar amounts of hve different benzaldehydes (23-27) and acetone cyanohydrin (28) in the presence of triethylamine. This resulted in release of cyanide ion and rapidly provided the cyanohydrin adducts (29-33), all as racemic mixtures of both enantiomers (DCL-D, Scheme 6.6). 

The BFD mutant library generated by epPCR was expressed in microtiter plates and 8000 clones were subjected to the carboligation assay with benzaldehyde 4 and dimethoxyacetaldehyde 8 as the substrates. The reaction was incubated for 24 h at 30 °C as suggested from experiments using the positive control strain... 

Clausen et al. (2005) found many similarities between odorants emitted from linseed oil as well as from a floor oil made of this linseed oil, concluding that the odorants of the linseed oil are also responsible for the odor of the floor oil. Of the 139 listed perceived odorants only 45 were identified by GC—MS library search and retention characteristics. Important odorants with a high detection frequency were acetaldehyde, propanal, butanal, pentanal, 2-pentenal, hexanal, 2-hexenal, heptanal, 2-heptenal, 2,4-heptadienal, octanal, 2-octenal, nonanal, 2-nonenal, 2-decenal, benzaldehyde, l-penten-3-one, l-penten-3-ol, pentyl oxiran, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, octanoic acid. 

Thrombin inhibitors (127), where Bohm et al. used LUDI to dock and score computationally available primary amines and then score the virtual library generated from benzaldehydes with the top-scoring hit. 

Synthesis of thiazolidinones [PEG -RMIM]X ionic liquids have been used for rapid synthesis of a small library of amido 4-thiazolidinones from amine, aldehyde, and mercaptoacid components (Scheme 7.22) [74]. In an initial feasibility study, acid-functionalized benzaldehydes were first coupled to the [PEG -RMIM]X ionic liquids. Imines were formed by reaction of the supported aldehydes with primary amines. The reactions were run in open vessels. Optimum results were obtained by irradiating the reaction mixture with low power at 100 °C for 20 min. The imines were then condensed with mercaptoacids to give the desired thiazolidinones which were then cleaved from the ionic liquid support by amide formation. Microwave irradiation was again used in this cleavage step. The procedure entailed addition of a small amount of solid potassium tert-butoxide to a premixed mixture of the amine and supported thiazolidinone and microwave exposure for 10-20 min at 100 or 150 °G depending on the amine used. In another study, a series of one-... 

Liskamp has reported the synthesis and the screening in asymmetric catalysis of a library of polymer-supported peptidosulfonamide [147]. Rt) or (5 -pyrrolydines 222 prepared in six steps from D or Z-tartaric acid were anchored onto Argonaut resin (0.41 mmol/g) to afford the corresponding supported pyrrolidines 223 (Scheme 91). The polymeric peptidosulfonamides 224 and 225 were then synthesized in four steps from the immobilized pyrrolidines 223. The different chiral polymers were tested in the titanium-mediated diethylzinc addition to benzaldehyde,/ -chlorobenzaldehyde, cyclohexanecarboxaldehyde and phenylacetaldehyde. Both yield and ee were very low with all these supported-ligands for the enantioselective reaction with the two aliphatic aldehydes. With aromatic aldehydes, the best results were observed with both leucine-derived supported peptidosulfonamides 224d and 225d. 

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