Syntheses and characterization of a new class of mono‐ and heterodinuclear derivatives of boron derived from Schiff bases

Abstract

Reactions of 2-isopropoxy-1, 3, 2-benzodioxaborole with equivalent amounts of Schiff base ligands having two hydroxyl groups (1a-3a) yield mononuclear derivatives with one residual hydroxy group. The reactions of these mononuclear derivatives with hexamethyldisilazane in a 2 : 1 ratio yield heterodinuclear derivatives. All these newly synthesized derivatives have been characterized by elemental analyses and molecular weight measurements. Tentative structures have been proposed on the basis of IR and NMR ( 1 H, 13 C, 11 B, 29 Si)spectral data and Fab-mass studies. Schiff bases and their corresponding mono-and heterodinuclear derivatives of boron have also been screened for antifungal activities.

Some Novel Dinuclear phenylboronates of biologically potent β‐enaminoesters: Synthesis, Spectroscopic characterization, antimicrobial activity and their antiandrogenic effect

“…It was observed that the compound 1a has more repressive effects on male albino rats than its corresponding methyl substituted β‐enamino esters. Antimicrobial activity (antibacterial and antifungal) and antiandrogenic activity of these compounds are found to be more potent in comparison to phenyboronic acid derivative of semicarbazoneand 1, 3, 2‐ benzodioxaborole derivatives of Schiff base ligands and boronate esters …”

“…A comparison of the antimicrobial (antifungal and antibacterial) activity of these compounds with those reported for phenylboronic acid derivatives of semicarbazone, [5] 1, 3, 2-benzodioxaborole derivatives of Schiff base ligands [1] and boronate esters [56] indicates that the antimicrobial potential of these ligands as well as their boron compounds is more than that of phenylboronic acid derivatives of semicarbazone derivatives, 1, 3, 2-benzodioxaborole derivatives and boronate esters. It may be due to the presence of two azomethine (>C=N) linkage in the β-enamino esters which might inhibit more effectively the enzyme production responsible for their activity more effectively.…”

“…In view of the above, we report in this article the synthesis and characterization of monomeric phenylboronates of β‐enamino esters. The proclaimed biological activities of organoboron compounds led us to investigate the antimicrobial activities of these phenylboronates. The antimicrobial activities of these boron compounds have been compared with phenyl boronic acid and corresponding ligands.…”

“…All these derivatives have been characterized by physico-chemical properties, elemental analyses and molecular weight measurements. The structures of these compounds have been proposed on the basis of IR, 1 H, 13 C, 11 B NMR spectral data and GC-mass spectrometry. Phenyl boronic acid, β-enamino esters and their respective phenylboronates derivatives have been screened for the antibmicrobial activities against pathogenic bacteria (B. subtilis and E. coli) and fungi (A. niger and P. peniculosum) to access their growth inhibiting potential.…”

Some heteroleptic boron derivatives and their isomers derived from Schiff bases and glycol: synthesis, characterization and antimicrobial activities

“…During the past two decades, boron compounds especially the four coordinated having bidentate ligands such as the 8-hydroxyquinoline (Hwang et al, 2005), pyridyl phenol (Li et al, 2005) and Schiff bases (Sharma et al, 2010) have been used as chemo sensors (Zhang and Zhang, 2005;Guliyev et al, 2009), organic light-emitting diodes (Evans et al, 2006), synthetic intermediate (Barba et al, 2001), catalysts (Faller and Lavoie, 2001;Pelagatti et al, 2005;Kilic et al, 2011) and in cancer therapy (Khan et al, 1992;Shelly et al, 1992). Consequently, much effort has been devoted to design and synthesize the boron compounds of Schiff bases to explore their broad applications.…”