Desymmetrization of pibrentasvir for efficient prodrug synthesis.

A novel and practical desymmetrization tactic is described to access a new class of pibrentasvir prodrugs. The homotopic benzimidazoles of pibrentasvir (PIB) are differentiated a one-pot di-Boc/mono-de-Boc selective -Boc protection and formaldehyde adduct formation sequence, both enabled by crystallization-induced selectivity. The first step represents the only known application of the Horeau principle of statistical amplification for -symmetric polyheterocycle regioselective functionalization.

Origin of Nanodroplet Formation Upon Dissolution of an Amorphous Solid Dispersion: A Mechanistic Isotope Scrambling Study.

It has been observed that certain amorphous solid dispersions (ASDs), upon dissolution, generate drug-rich amorphous nanodroplets. These nanodroplets, present as a dispersed phase, can potentially enhance oral bioavailability of poorly soluble drugs by serving as a drug reservoir that efficiently feeds the continuous aqueous solution phase following absorption of drug. The purpose of this study is to probe the formation mechanism of the nanodroplets.

Special deliverers. Interview by Carol Davis.

Forty years on, a group of midwives who joined forces in Liverpool as nursing students are now contemplating retirement. Their working lives have been revolutionised in the interim.

Synthesis and characterization of chemically condensed oligoethylenimine containing beta-aminopropionamide linkages for siRNA delivery.

Polyethylenimines (PEI) are often inefficient in gene knockdown experiments with small interfering RNA (siRNA), presumably due to the strong complexing properties. A more efficient and potentially degradable oligoethylenimine-based carrier was synthesized by the condensation of 800 molecular weight PEI oligomers with hexanedioldiacrylate. Reaction conditions were chosen such that Michael reaction occurs followed by complete N-acylation of all residual ester bonds resulting in beta-aminopropionamide linkage sites and an average molecular weight of 30,000.

Synthesis of novel and uniquely shaped 3-azabicyclo[4.2.0]octan-4-one derivatives by sequential Ugi/[2+2] ene-enone photocycloadditions.

[structure: see text]. We report a new methodology for the construction of novel and uniquely shaped 3-azabicyclo[4.2.