Dinickel-Catalyzed N=N Coupling Reactions for the Synthesis of Hindered Azoarenes.

Azoarenes are the largest class of photoswitching molecules, and they have a broad range of applications in photopharmacology and materials science. Azoarenes possessing -substitution often display improved properties, including isomerization under visible light irradiation, near-quantitative switching, and long thermal half-lives in the form. The synthesis of hindered -substituted azoarenes is often low-yielding using established oxidative or reductive coupling methods.

Rapid depletion of "catch-and-release" anti-ASGR1 antibody in vivo.

Targeting antigens with antibodies exhibiting pH/Ca-dependent binding against an antigen is an attractive strategy to mitigate target-mediated disposition and antigen buffering. Studies have reported improved serum exposure of antibodies exhibiting pH/Ca-binding against membrane-bound receptors. Asialoglycoprotein receptor 1 (ASGR1) is a membrane-bound receptor primarily localized in hepatocytes.

Redox Approaches to Carbene Generation in Catalytic Cyclopropanation Reactions.

Transition metal-catalyzed carbene transfer reactions have a century-old history in organic chemistry and are a primary method for the synthesis of cyclopropanes. Much of the work in this field has focused on the use of diazo compounds and related precursors, which can transfer a carbene fragment to a catalyst with concomitant loss of a stable byproduct. Despite the utility of this approach, there are persistent limitations in the scope of viable carbenes, most notably those lacking stabilizing substituents.

Catalytic Asymmetric Synthesis of Zinc Metallacycles.

Transition-metal-catalyzed reductive coupling reactions of alkynes and imines are attractive methods for the synthesis of chiral allylic amines. Mechanistically, these reactions involve oxidative cyclization of the alkyne and the imine to generate a metallacyclic intermediate, which then reacts with H or a H surrogate to form the product. As an alternative to this hydrogenolysis pathway, here we show that transmetalation to zinc can occur, forming a zinc metallacycle product.

Nucleophilic Carbenes Derived from Dichloromethane.

Nickel PyBox catalysts promote nucleophilic cyclopropanation reactions using CH Cl as a methylene source and Mn as a stoichiometric reductant. The substrate scope includes a broad range of alkenes bearing electron-withdrawing substituents, including esters, amides, ketones, nitriles, sulfones, phosphonate esters, trifluoromethyl groups, and electron-deficient arenes. Enantioselective cyclopropanations of α,β-unsaturated esters have been developed using chiral PyBox ligands.