A novel [3 + 2] cycloaddition between nitrile ylides and diazonium salts was well-established. This copper-catalyzed three-component reaction was distinguished by mild conditions, ready availability, and operational simplicity, thus opening access to 1,2,4-triazoles with a diverse set of substitution patterns.

A new cross-coupling reaction between sulfonyl hydrazides and diazo compounds has been established, leading to a variety of β-carbonyl sulfones in good yields. This methodology was distinguished by simple manipulation, easily available starting materials, and wide substrate scope. A plausible mechanism involving a radical process was proposed based upon the experimental observations and literature.

A new strategy has been developed for the synthesis of α-amino acid esters via a tandem hydrolysis/decarboxylation/nucleophilic substitution using TBAI/TBHP.

The interception of cobalt-based carbene radicals with α-aminoalkyl radicals was combined with the Kornblum-DeLaMare reaction and provides β-ester-γ-amino ketones, which are otherwise difficult to obtain in high chemoselectivity. Mechanistically, this transformation is an interplay of cobalt-based carbene radicals, organoradicals, and ionic intermediates and involves the construction of two C-C bonds and one C=O bond in a one-pot process. The reaction also features a wide substrate scope and is highly efficient and insensitive to moisture and air.

A new radical-polar crossover reaction has been developed involving the combination of a tandem radical reaction and KornblumDeLaMare rearrangement in a one-pot process. This simple methodology allows for the construction of polyfunctionalized carbonyl compounds via the oxidative coupling of 1,3-dioxolanes with electron-deficient alkenes and vinylarenes in the presence of Co(salen) and TBHP under mild conditions. This reaction also exhibited high functional group tolerance, wide substrate scope, and operational simplicity.

Eine Tandemreaktion für den Aufbau von β-Ester-γ-aminoketonen kombiniert Carbenradikale, organische Radikale und eine ionische Kornblum-DeLaMare-Reaktion in einem einzigen Katalysezyklus. In ihrer Zuschrift auf S. 1247 ff. zeigen X. Wan und Mitarbeiter, dass das Cobalt-basierte Carbenradikal statt einer einfachen Addition an ein Olefin mit α-Aminoalkylradikalen abgefangen werden kann.