Design and Evaluation of Highly Selective Human Immunoproteasome Inhibitors Reveal a Compensatory Process That Preserves Immune Cell Viability.

The pan-proteasome inhibitor bortezomib demonstrated clinical efficacy in off-label trials of Systemic Lupus Erythematosus. One potential mechanism of this clinical benefit is from the depletion of pathogenic immune cells (plasmablasts and plasmacytoid dendritic cells). However, bortezomib is cytotoxic against nonimmune cells, which limits its use for autoimmune diseases.

A solid-phase approach for the synthesis of α-aminoboronic acid peptides.

A solid-phase synthesis of α-aminoboronic acid peptides using a 1-glycerol polystyrene resin is described. Standard Fmoc solid-phase peptide chemistry is carried out to construct bortezomib and ixazomib. This approach eliminates the need for liquid-liquid extractions, silica gel column chromatography, and HPLC purifications, as products are isolated in high purity after direct cleavage from the resin.

A General Strategy for the Construction of Functionalized Azaindolines via Domino Palladium-Catalyzed Heck Cyclization/Suzuki Coupling.

The preparation of substituted azaindolines utilizing a domino palladium-catalyzed Heck cyclization/Suzuki coupling is described. The approach is amenable for the construction of all four azaindoline isomers. A range of functional groups such as esters, amides, ketones, sulfones, amines, and nitriles are all tolerated under the reaction conditions.

Synthesis of Enantioenriched Indolines by a Conjugate Addition/Asymmetric Protonation/Aza-Prins Cascade Reaction.

A conjugate addition/asymmetric protonation/aza-Prins cascade reaction has been developed for the enantioselective synthesis of fused polycyclic indolines. A catalyst system generated from ZrCl4 and 3,3'-dibromo-BINOL enables the synthesis of a range of polycyclic indolines in good yields and with high enantioselectivity. A key finding is the use of TMSCl and 2,6-dibromophenol as a stoichiometric source of HCl to facilitate catalyst turnover.