A scalable synthetic method is described for both the preparation of ultrasmall palladium nanoparticles and their subsequent use in catalyzing an αarylation reaction of nitriles in aqueous micelles. This method involves the intermediacy of carbanions or keteniminates, which are presumably stabilized by the micellar environment rather than being quenched with water. These Pd nanoparticles are thoroughly characterized. Mechanistic studies using 31 P NMR spectroscopy revealed the binding of phosphine ligand with the Pd surface and control experiment confirmed the zero-oxidation state of palladium. The scope of the transformation is demonstrated over 35 examples, including one at 50 g scale.

Using micelles of FI-750-M, visible light, photocatalysts, and inexpensive halogenating reagents, such as N-bromosuccinimide and N-chlorosuccinimde, selective oxyhalogenations of alkynes were achieved in water under very mild conditions. No halogenation at the aromatic rings was detected, and control experiments revealed the radical pathway. The easily conducted protocol exhibited high reproducibility, was readily adjusted to gram scale, and allowed for recycling of reaction medium and catalyst.

While organo-substituted diazenes (R 1 −N N−R 2 with R = alkyl, aryl) are a well-studied class of compounds, much less is known about their heavier group 14 analogues, notably because of their perceived instability. We report herein a general oxidative protocol to prepare various N-aryl-N′-silyldiazenes by a fast and mild dehydrogenation of the corresponding silylhydrazines using di-tert-butylazodicarboxylate as an oxidant. The optical properties of these stable blue to purple silyldiazenes were also studied by UV/visible absorption spectroscopy and supported by TD-DFT calculations.

A method for the catalytic generation of functionalized aryl alkali metals is reported. These highly reactive intermediates are liberated from silyl‐protected aryl‐substituted diazenes by the action of Lewis basic alkali metal silanolates, resulting in desilylation and loss of N2. Catalytic quantities of these Lewis bases initiate the transfer of the aryl nucleophile from the diazene to carbonyl and carboxyl compounds with superb functional‐group tolerance. The aryl alkali metal can be decorated with electrophilic substituents such as methoxycarbonyl or cyano as well as halogen groups. The synthesis of a previously unknown cyclophane‐like [4]arene macrocycle from a 1,3‐bisdiazene combined with a 1,4‐dialdehyde underlines the potential of the approach.

The photoswitchable motif of azobenzenes is of great importance across the life and materials sciences. This maintains a constant demand for their efficient synthesis, especially that of non-symmetric derivatives. We disclose here a general strategy for their synthesis through an unprecedented C(sp 2 )À N(sp 2 ) cross-coupling where functionalized aryl-substituted diazenes masked with a silyl group are employed as diazenyl pronucleophiles. These equivalents of fragile diazenyl anions couple with a diverse set of (hetero)aryl bromides under palladium catalysis with no loss of dinitrogen. The competing denitrogenative biaryl formation is fully suppressed. The reaction requires only a minimal excess, that is 1.2 equivalents, of the diazenyl component. By this, a broad range of azoarenes decorated with two electron-rich/deficient aryl groups can be accessed in a predictable way with superb functional-group tolerance.