Phosphonium salts with a dihydroxynaphthyl substituent: versatile synthesis and evaluation of antimicrobial activity

o-Hydroxyarylphosphanes: Strategies for Syntheses of Configurationally Stable, Electronically and Sterically Tunable Ambiphiles with Multiple Applications

o-Hydroxyarylphosphanes are fascinating compounds by their multiple-reactivity features, attributed to the ambident hard and soft Lewis- and also Brønstedt acid-base properties, wide tuning opportunities via backbone substituents with ±mesomeric and inductive, at P and in o-position to P and O also steric effects, and in addition, the configurational stability at three-valent phosphorus. Air sensitivity may be overcome by reversible protection with BH3 , but the easy oxidation to P(V)-compounds may also be used. Since the first reports on the title compounds ca. 50 years ago the multiple reactivity has led to versatile applications. This includes various P-E-O and P=C-O heterocycles, a multitude of O-substituted derivatives including acyl derivatives for traceless Staudinger couplings of biomolecules with labels or functional substituents, phosphane-phosphite ligands, which like the o-phosphanylphenols itself form a range of transition metal complexes and catalysts. Also main group metal complexes and (bi)arylphosphonium-organocatalysts are derived. Within this review the various strategies for the access of the starting materials are illuminated, including few hints to selected applications.

Cationic Organophosphorus Chromophores: A Diamond in the Rough among Ionic Dyes

Tunable electron-accepting properties of the cationic phosphorus center, its geometry and unique preparative chemistry that allows combining this unit with diversity of π-conjugated motifs, define the appealing photophysical and electrochemical characteristics of organophosphorus ionic chromophores. This Minireview summarizes the achievements in the synthesis of the π-extended molecules functionalized with P-cationic fragments, modulation of their properties by means of structural modification, and emphasizes the important effect of cation-anion interactions, which can drastically change physical behavior of these two-component systems.

Synthesis and Antimicrobial Properties of Novel Phosphonium Salts Bearing 1,4-Dihydroxyaryl Fragment

A versatile two-step pathway to the synthesis of triaryl(2,5-dihydroxy-6-methyl-3-(propan-2-yl)phenyl)- and triaryl(1,4-dihydroxynaphthyl)phosphonium salts from triarylphosphonium trifluoroacetates was developed. The reaction proceeds under mild conditions (20 °C, CH₂ Cl₂ ) with high yields (88-95 %). Some representatives of this series possess low hemolytic and high bactericidal activity against Gram-positive bacteria.