Synthesis and Characterization of Bola-Amphiphilic Porphyrin-Perylenebisimide Architectures.

We report on the synthesis and characterization of a family of three water-soluble bola-amphiphilic zinc-porphyrin-perylenebisimide triads containing oligo carboxylic-acid capped Newkome dendrons in the periphery. Variations of the perylenebisimide (PBI) core geometry and dendron size (G1 and G2 dendrons with 3- and 9-carboxylic acid groups respectively) allow for tuning the supramolecular aggregation behavior with respect to variation of the molecular architecture. The triads show good solubility in basic aqueous media and aggregation to supramolecular assemblies. Theoretical investigations at the DFT level of theory accompanied by electrochemical measurements unravel the geometric and electronic structure of the amphiphiles. UV/Vis and fluorescence titrations with varying amounts of THF demonstrate disaggregation.

Impact of Fluoroalkyl Substituents on the Physicochemical Properties of Saturated Heterocyclic Amines.

The physicochemical properties (pKa (H), log P, and aqueous solubility) of fluoroalkyl-substituted heterocyclic amines were profiled to facilitate the amines' rational application in medicinal chemistry research. The features of fluorine-containing compounds were compared to those of the corresponding parent non-fluorinated heterocycles and the corresponding fluorinated n-alkylamines. Amine basicity was observed to change in a monotonic fashion depending on the fluorination pattern. Although the introduction of fluoroalkyl groups had complex effects on the lipophilicity and aqueous solubility of the compounds, possible contributions of the fluorination pattern, ring size, and conformation of the substituent in the ring were addressed for a series of derivatives. The summarized data provide a useful guideline for the application of fluorinated motifs for fine-tuning a compound's properties related to drug discovery.

Effect of gem-Difluorination on the Key Physicochemical Properties Relevant to Medicinal Chemistry: The Case of Functionalized Cycloalkanes.

Physico-chemical properties important to drug discovery (pKa , LogP, and aqueous solubility), as well as metabolic stability, were studied for a series of functionalized gem-difluorinated cycloalkanes and compared to those of non-fluorinated and acyclic counterparts to evaluate the impact of the fluorination. It was found that the influence of the CF2 moiety on the acidity/basicity of the corresponding carboxylic acids and amines was defined by inductive the effect of the fluorine atoms and was nearly the same for acyclic and cyclic aliphatic compounds. Lipophilicity and aqueous solubility followed more complex trends and were affected by the position of the fluorine atoms, ring size, and even the nature of the functional group present; also, significant differences were found for the acyclic and cyclic series. Also, gem-difluorination either did not affect or slightly improved the metabolic stability of the corresponding model derivatives. The presented results can be used as a guide for rational drug design employing fluorine and establish the first chapter in a catalog of the key in vitro properties of fluorinated cycloalkanes.