Mild, Efficient, and Regioselective Synthesis of Diiodophenyl­boronic Acid Derivatives via Metal–Iodine Exchange of 5-Substituted 1,2,3-Triiodoarenes

Abstract

Unique 2,6-diiodophenylboronic acid and 2,3-diiodophenylboronic acid derivatives have been synthesized via regioselective metal–iodine exchange (MIE) of 5-substituted 1,2,3-triiodoarenes. The regio­selectivity of the reaction per se is remarkably controlled by the nature of the C5 substituent providing the desired diiodophenylboronic acids in moderate to good yields and with high site selectivity. The diiodophenylboronic acids were then examined for in vitro antimicrobial activity against four strains of bacteria Micrococcus luteus (ATCC 9341), Bacillus cereus (ATCC 11778), Escherichia coli (ATCC 25922), and Serratia marcescens (ATCC 27117) and one fungal strain Candida albicans using well diffusion assay and dilution method. It indicated that 5-fluoro-2,3-diiodophenylboronic acid possesses the most potent antibacterial and antifungal activity with MIC of 2.6 mg/mL for M. luteus and C. albicans. This report discloses a one-step protocol to access hitherto unknowns 2,6-diiodophenylboronic acid and 2,3-diiodophenylboronic acid derivatives that is scalable, good in scope, no chromatography is needed, and these compounds are difficult to prepare by other means.

Organoboronic acids/esters as effective drug and prodrug candidates in cancer treatments: challenge and hope

“…Organoboron derivatives can also be used as antibacterial agents 30 or antifungal agents such as diazaborine 3 31 , oxazaborolidine 4 32 , diphenyl borinic ester 5 33 , tavaborole 6 (Kerydin®) 34 , and iodinated benzoboroxoles 7 , 8 35 . In addition, crisaborole 9 (Eucrisa®) 36 is used for the treatment of mild-to-moderate atopic dermatitis (eczema) in adults and children.…”

l-Proline-Catalyzed Three-Component Reaction of 4-Chloro-3-formylcoumarin, Sodium Sulfide, and α-Halo Ketones: A Direct Approach to Thieno[3,2-c]coumarins

“…25 Thiophene is a sulfur based heterocyclic ring that demonstrates a wide range of pharmaceutical activities and it is found in many marketed drugs and organic materials. [26][27][28][29][30][31][32][33][34][35] In this perspective, the combination of thiophene and coumarin in one molecule has gained the attention of many researchers [36][37][38] due to the expected synergistic activity of both scaffolds. The fusion of thiophene to coumarin's pyrone ring results in three structural isomers based on the sulfur atom position and one of these isomers is thieno [3,2-c]coumarin.…”