Diyne-steered switchable regioselectivity in cobalt(II)-catalysed C(sp2)-H activation of amides with unsymmetrical 1,3-diynes.

The regiochemical outcome of a cobalt(II) catalysed C-H activation reaction of aminoquinoline benzamides with unsymmetrical 1,3-diynes under relatively mild reaction conditions can be steered through the choice of diyne. The choice of diyne provides access to either 3- or 4-hydroxyalkyl isoquinolinones, paving the way for the synthesis of more highly elaborate isoquinolines.

Electrochemical rhodium catalysed alkyne annulation with pyrazoles through anodic oxidation - a metal oxidant/additive free methodology.

Pyrazole and its derivatives are important azole heteroarenes prevalent in pharmaceutical compounds and have been used as ligands for protein binding, making them valuable targets for synthetic applications. Herein we disclose an electrochemical intermolecular C-H/N-H oxidative annulation of 2-phenylpyrazoles with alkynes using a rhodium(III) redox regime without any external metal oxidants in a water compatible solvent system. Both symmetrical and unsymmetrical alkynes were shown to be compatible with the optimized conditions.

Correction: Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context.

[This corrects the article DOI: 10.1039/D1RA06851B.].

Tandem Iridium-Catalyzed Decarbonylative C-H Activation of Indole: Sacrificial Electron-Rich Ketone-Assisted Bis-arylsulfenylation.

Described herein is a decarbonylative tandem C-H bis-arylsulfenylation of indole at the C2 and C4 C-H bonds through the use of pentamethylcyclopentadienyl iridium dichloride dimer ([Cp*IrCl2]2) catalyst and disulfides. A new sacrificial electron-rich adamantoyl-directing group facilitates indole C-H bis-functionalization with a traceless in situ removal. Various differently substituted disulfides can be easily accommodated in this reaction by a coordination to Ir(III) through the formation of six- and five-membered iridacycles at the C2 and C4 positions, respectively. Mechanistic studies show that a C-H activation-induced C-C activation is involved in the catalytic cycle.

Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context.

Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions. This thin film-format demonstrated good catalytic efficiency (TON up to 3.4 × 103) and stability. Incorporation into a quartz crystal microbalance (QCM) instrument illustrated the potential for using this approach in lab-on-a-chip-based synthesis applications.