Synthesis of cis‐1,2‐diol‐type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation

Abstract

Two cis‐1,2‐diol‐type chiral ligands (T1 and T2) and their tri‐coordinated chiral dioxaborinane (T(1–2)B(1–2)) and four‐coordinated chiral dioxaborinane adducts with 4‐tert‐butyl pyridine sustained by N → B dative bonds (T(1–2)B(1–2)‐N) were synthesized and characterized by various spectroscopic techniques such as NMR (1H, 13C, and 11B), FT‐IR and UV–Vis spectroscopy, LC–MS/MS, and elemental analysis. It was suggested that both ferrocene and trifluoromethyl groups played key roles in the catalytic and biological studies because they could tune the solubility of the chiral dioxaborinane complexes and adjust the strength of intermolecular interactions. To assess the biological activities of newly synthesized chiral dioxaborinane compounds, DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) radical scavenging, reducing power, antibacterial, DNA binding, and DNA cleavage activities were tested. Then, all chiral dioxaborinane complexes were investigated as catalysts for the asymmetric transfer hydrogenation of various ketones under suitable conditions. The results indicated that the chiral dioxaborinane catalysts performed well with high yields.

Recent Advances in Organocatalyzed Asymmetric Reduction of Prochiral Ketones: An Update

“…In early 2020, the same group 12 synthesized several dioxaborinane complexes 4a – d and examined their properties for ATH of various acetophenones and dialkyl ketones 5 (Scheme 2 ). Similarly, the complexes 4a and 4b possessing a ferrocenyl substituent showed better enantioselectivity.…”

Polimer grupları içeren yeni bir boronik asit ve boronat esterleri: spektroskopik özelliklerinin sentezi ve araştırılması

“…Boron esters are synthesized as a result of dehydration of boronic acid with diols. Since ester formation can be achieved with high efficiency, multipurpose boronic acids and different diol derivatives have been used to prepare various structures [7,8]. Also, extended stability obtained under various alcohol and water conditions provides a platform for the boroncontaining chemicals to sustain and conformationally survive during synthesis.…”

“…The formation of boronate ester-based polymers (2-5) was achieved by the disappearance of υ(-OH) vibrations after esterification between the boronic acid-based polymer (1) and diols by dehydration by heating at reflux with a Dean Stark trap. In the spectrum of the obtained boronate ester-based polymers (2-5), the disappearance of υ(-OH) vibrations after esterification and the formation of a new peak in the range of 1361-1356 cm -1 revealed the presence of υ(B-O) groups in the polymer chain[7,[20][21][22]. However, in the FT-IR spectra of all polymers (1-5) it was observed it appears that characteristic peaks belonging to the aromatic and aliphatic υ(C-H) groups in intervals 3072-3024 and 2989-2814 cm -1 , respectively, and the synthesized polymers are in harmony with the proposed structures.polymer (1) and 1,2-diol groups were investigated by NMR.…”