Fluorescent dyes have been widely utilized as chemical sensors and in photodynamic therapy, but exploitation of their redox-active nature in chemical reactions has remained mostly unexplored. This report describes the isolation of a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based radical. The redox-active nature of the BODIPY compound can be utilized in combination with a guanidine center, the basicity of which can be manipulated by greater than 14 pK units, to promote the conversion of protons and electrons into H-atoms for transfer to substrate molecules.

The synthesis and characterization of chiral and achiral diamines containing one and two BODIPY fragments is described.

Hydride transfer promoted by the coordination of a substrate molecule to a Lewis acid is a critical step in many catalytic transformations. This computational study investigates the nature of the interaction between a polar substrate molecule and a Lewis acid by examining the influence of Lewis acid strength on the ability to reduce (transfer a hydride to) the coordinated substrate molecule. To investigate this interaction, the coordination of 10 probe substrates to seven Lewis acids was analyzed. Coordination of the probe substrate molecules to a Lewis acid resulted in a more favorable reduction of the substrate molecule by 20-70 kcal mol. Further examination of the coordination of the substrate molecules to Lewis acids of varying Lewis acid strengths resulted in a direct linear correlation between the ability of the Lewis acid-substrate adduct to accept a hydride and the Lewis acid strength. The linear correlations also revealed that between 44 and 70% of the Lewis acidity of the Lewis acids translated to the Lewis acid-substrate adducts. From the results obtained in this study, the minimum Lewis acid strength needed to activate the substrates for the reduction with [BH] and the implications of employing a Lewis acid to promote the reduction of an unsaturated polar substrate in catalytic reactions are also described.

This report describes the incorporation of BODIPY dyes into the ligand framework of a borane to generate a family of molecular boranes that are capable of exhibiting tunable Lewis acidities through BODIPY-based redox events.