Design, synthesis and utilization of a novel coupling reagent for the preparation of O-alkyl hydroxamic acids
作者:Nagnnath D. Kokare、Rahul R. Nagawade、Vipul P. Rane、Devanand B. Shinde
DOI:10.1016/j.tetlet.2007.04.058
日期:2007.6
An efficient novel reagent, phosphoric acid diethyl ester 2-phenyl-benzimidazol-1-yl ester, was designed, and synthesized and its applicability was demonstrated for the preparation of O-alkyl hydroxamic acids. The O-alkyl hydroxamic acids of N-protectedaminoacids were also synthesized. The enantiomeric purity of the synthesized compounds were measured using chiral HPLC and the degree of racemization
<i>N</i>-[(Diphenoxyphosphoryl)oxy]-2-phenyl-1<i>H</i>-benzimidazole as a versatile reagent for synthesis<i>O</i>-alkylhydroxamic acids
作者:Nagnnath D. Kokare、Devanand B. Shinde
DOI:10.1002/jhet.5570450406
日期:2008.7
Highly efficient reagent, N-[(diphenoxyphosphoryl)oxy]-2-phenyl-1H-benzimidazole was synthesized and its applicability was demonstrated for the synthesis of O-alkyl hydroxamic acids. The efficiency of the reagent was evaluated through the synthesis of range of O-alkyl hydroxamic acids from aromatic carboxylic acids as well as N-protected amino acids. The enatiomeric purity of synthesized compounds
The direct conversion of various carboxylic acids, that include stericallyhindered amino acids and di-peptides, to O-benzyl hydroxamates is demonstrated using sulfonate esters of benzotriazoles under ambient and milder conditions without significant racemization. This simple and efficient protocol is extended to the synthesis of O-benzyl hydroxamates, using in situ generated solid supported TsOBt
The peculiar behavior of Picha in the formation of metallacrown complexes with Cu(<scp>ii</scp>), Ni(<scp>ii</scp>) and Zn(<scp>ii</scp>) in aqueous solution
metallacrown complexes formed by picolinehydroxamic acid (Picha) with Cu(II), Ni(II) and Zn(II) in aqueous solution has been determined by potentiometry, and the speciation models were validated by ESI-MS and UV-visible spectrophotometry. Cu(II) and Zn(II) form 12-MC-4 species as the unique metallacrowns present in the solution. While for Cu(II) the 12-MC-4 is slightly less stable than that obtained with alaninehydroxamic