Synthesis Of Hydroxamic Acids Research Articles

To robotize chemistry laboratories. An example of organic synthesis: 2‐Boc‐amino‐N‐hydroxy‐3‐phenyl‐propionamide

The paper describes the development of periodic modules used for the peptide synthesis of hydroxamic acid. A powder conveyor using the principle of positive weighing distribution is described. Purification is provided using automatic filtration and a liquid— liquid extraction module separation device. Device quality is improved using failure mode and effects analysis.

Simple syntheses of hydroxamic acids and their conversion into α-hydroxy and α-amino acids

The nucleophilic ring opening of gem-dicyanoepoxides by LiBr or Li 2NiBr 4, in the presence of hydroxylamine derivatives leads to new α-halo hydroxamic acids. These compounds has been used in the synthesis of α-functionalized hydroxamic acids, α-hydroxy and α-amino acids in good yields.

Solution and solid-phase synthesis of hydroxamic acids via palladium catalysed cascade reactions

The elaboration of a series of aryl iodides into heterocyclic hydroxamates proceeds in good to excellent yield in a palladium catalysed termolecular cascade reaction involving carbon monoxide and protected hydroxylamines. Deprotection affords a range of novel heterocyclic hydroxamic acids. In a related process, N-benzyloxyimides were synthesised in a pentamolecular cascade. The hydroxamic acids were also synthesised using resin-bound hydroxylamine derivatives in a solid-phase cascade process.

Synthesis of hydroxamic acids using SynPhase™ crowns: Development of the hydroxylamine trityl linker

The synthesis of peptide and small molecule hydroxamic acids utilising SynPhase™ crowns is demonstrated. A hydroxylamine trityl linker is generated from chlorotrityl derivatised Synphase™ crowns by reaction with N-hydroxyphthalimide followed by subsequent deprotection. The loading of hydroxylamine crowns is quantified spectrophotometrically by measuring phthalhydrazide absorbance at 346 nm.

Solid-phase synthesis of hydroxamic acid based TNF-α convertase inhibitors

An acid-sensitive linker for the solid phase synthesis of hydroxamic acids is described. Hydroxamic acid based TNFα inhibitors have been prepared by solid phase synthesis: derivatisation of N2-[4-(N-oxyamino)-2R-isobutyl-3S-aminosuccinyl]-L-tert-leucine-N1-methylamide grafted on Sasrin® resin and subsequent acidic cleavage afforded hydroxamic acids in good yields and with good purity.

ChemInform Abstract: New Hydroxylamines for the Synthesis of Hydroxamic Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

New hydroxylamines for the synthesis of hydroxamic acids

O-2,4-Dimethoxybenzyl hydroxylamine and O-2,4-dimethoxybenzyl-N-2,4,6-trimethoxybenzyl hydroxylamine have been prepared and used for the preparation of hydroxamic acid based inhibitors of biological interest.

Monohydroxamic acid biosynthesis

Hydroxamic acids (HA), with the general formula R–CO–NHOH, are chelating agents which may be used in a number of interesting applications, such as medicine and waste water treatment. In this paper, we describe the enzymatic synthesis of HA with various chain lengths (from C2 to C18), using three microbial enzymes. For short- and middle-chain HA synthesis, using amidases from Rhodococcus sp. R312, the optimal working pH was found to be pH 7 or 8, depending on the amide substrate used. Different Michaelis–Menten constants were also determined. For fatty HA synthesis, using lipase from Candida parapsilosis, the optimal working conditions were determined to be pH 6, 1 M hydroxylamine and 40°C. Because of the favorable bioconversion yields achieved, the enzymatic synthesis of HA with the appropriate biocatalysts appears to be an interesting alternative to chemical synthesis.

Solid Phase Synthesis of Hydroxamic Acids

Solid Phase Synthesis of Hydroxamic Acids

Solid supported synthesis of hydroxamic acids

A novel approach to the solid supported synthesis of hydroxamic acids was developed. It employs oxime resin and unlike all previously reported methods allows for the use of acid labile protecting groups. Cleavage is induced by treatment with tert-butyldimethylsilyl-O-hydroxylamine, followed by silyl group deprotection with trifluoroacetic acid.

A novel linkage for the solid-phase synthesis of hydroxamic acids

A novel linkage for the solid-phase synthesis of hydroxamic acids is described and its facile application for the solid phase synthesis of peptidyl, succinyl and urea-type hydroxamic acids is illustrated. Cleavage is induced under mild acidic conditions by treatment with formic acid in THF, providing hydroxamic acids in high purity and fair to good yields.

A New and Efficient Solid Phase Synthesis of Hydroxamic Acids.

A New and Efficient Solid Phase Synthesis of Hydroxamic Acids.

N-Fmoc-aminooxy-2-chlorotrityl polystyrene resin: A facile solid-phase methodology for the synthesis of hydroxamic acids

Using the new compound N-Fmoc-hydroxylamine, 1 we have generated a facile route to a high loading, acid labile solid-phase resin bearing a hydroxylamine linker. The novel N-Fmoc-aminooxy-2-chlorotrityl polystyrene 2 showed generic utility for the construction of hydroxamic acids, including peptidyl hydroxamic acids.

ChemInform Abstract: A Method for the Synthesis of Hydroxamic Acids on Solid Phase.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A TFA-cleavable linkage for solid-phase synthesis of hydroxamic acids

A novel linkage for the solid-phase synthesis of hydroxamic acids is described. The linkage is stable to all reagents commonly used in Fmoc peptide synthsis. Cleavage is induced by treatment with trifluoroacetic acid, providing hydroxamic acids in high purity and good yields.

A method for the synthesis of hydroxamic acids on solid phase

Wang resin 1 was modified using a Mitsunobu reaction to give resin bound O-hydroxylamine 3. This resin was acylated and the adduct cleaved from the resin as a hydroxamic acid on treatment with TFA. Series of tripeptide, and sulfonamido 9 hydroxamic acids which act as inhibitors of metalloproteinases have been prepared. Resins more sensitive to acid cleavage can also be modified to simplify the work-up procedure.

ChemInform Abstract: Synthesis of Hydroxamic Acids: Pd/BaSO4 as a New Catalyst for the Deprotection of O‐Benzyl Hydroxamates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of hydroxamic acids: [formula omitted] as a new catalyst for the deprotection of O-benzyl hydroxamates

Pd BaSO 4 was found to be an efficient catalyst in the deprotection of O-benzyl hydroxamates via hydrogenation to give the corresponding hydroxamic acids without further reduction to amides.

ChemInform Abstract: Useful Hydroxylamine Derivatives for the Synthesis of Hydroxamic Acids.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Useful hydroxylamine derivatives for the synthesis of hydroxamic acids.

N-BOC-O-THP and N-BOC-O-TBDMS, two derivatives of hydroxylamine have been synthesized and used for the preparation of hydroxamic acids of biological interest.