The widespread use of alkyl boronic acids and esters is frequently hampered by the challenges associated with their preparation. We describe a simple and practical method to rapidly access densely functionalized alkyl boronate esters from abundant carboxylic substituents. This broad-scope nickel-catalyzed reaction uses the same activating principle as amide bond formation to replace a carboxyli...

Hydroxamic acids have been reported to be potent and specific inhibitors of urease (EC 3.5.1.5) activity of plant and bacterial origin. The present investigation was performed on the inhibitory effect of hydroxamic acid derivatives of naturally occurring amino acids on the urease activity of the Jack Bean and the alimentary tracts of rats. Methionine-hydroxamic acid was the most powerful inhi...

A one-pot, three-step protocol for the preparation of Grignard reagents from organobromides in a ball mill and their subsequent reactions with gaseous carbon dioxide (CO2) or sodium methyl carbonate providing aryl alkyl carboxylic acids up to 82 % yield is reported. Noteworthy are short reaction times significantly reduced solvent amounts [2.0 equiv. liquid assisted grinding (LAG) conditions]. ...

The effect of alkyl substituents on the C-phenyl and/or the N-Phenyl ring of benzophenylhydroxamic acid on their molecular structure and hydrogen bonding has been investigated. The predominant configuration in CHCl3 is determined by steric and electronic effects. Substituents on the C-phenyl ring favor the cis configuration, while substituents in the N-phenyl ring favor a trans c...

A. Introduction B. Acid-Catalysed Esterification and Transesterification 1. General mechanism 2. Methanolic hydrogen chloride 3. Methanolic sulfuric acid 4. Boron trifluoride-methanol 5. Other acidic catalysts C. Base-Catalysed Transesterification 1. General mechanism 2. Sodium and potassium methoxide catalysts 3. Organic base catalysis D. Diazomethane and Related Reagents 1. Diazomethane and m...

Arrangement of several hydroxamic acid-derived substituents along the cavity of a cyclodextrin ring leads to compounds that detoxify tabun in TRIS-HCl buffer at physiological pH and 37.0 °C with half-times as low as 3 min.

Horseradish peroxidase forms spectroscopically distinct, reversible complexes with hydroxamic acids (R-CONHOH), hydrazides (RCO-NHNH2), amides (RCONH2), and oc-hydroxyketones (RCO--CHsOH). Binding of these compounds to the enzyme depends on the polar and steric character of R and the hydrogen bonding capacity of-COX-Y (X-Y = NH-OH, NH-NH,, NH-H, CH,OH). Hydroxamate anions and hydrazide cations ...

Roots of young seedleings of barnyard grass, maize, rye and wheat secret hydroxamic acids. Their compexes with Fe/III/-ions are available sources of iron. It is possible that the cyclic hydroxamic acids play a role in the alternative mechanism of iron uptake. The hydroxamic acids secreted by barnayard grass roots have an allelopathic role by inhibiting the roots growth of rice. Acta Biol Szeged...