Cocatalysis by pivalic acid or copper bromide allows a very fast, clean, and high-yielding palladium-catalyzed coupling of a large array of aryl, thienyl, and pyridyl halides with cyclic nitrones, including DMPO. The study of the reaction conditions, scope, and mechanism is presented. Applied to the chiral nitrone MiPNO, this transformation provides a straightforward access to enantiopure α-methyl α-arylglycine esters.

(Pinacolato)boryl ortho-silyl(hetero)aryl triflates are presented as a new class of building blocks for arylation. They demonstrate unique versatility by delivering boronate or (hetero)aryne reactivity chemoselectively in a broad range of transformations. This approach enables the unprecedented postfunctionalization of fluoride-activated (hetero)aryne precursors, for example, as substrates in transition-metal catalysis, and offers valuable new possibilities for aryl boronate postfunctionalization without the use of specialized protecting groups.

Various functionalized aryl boronic esters derived from hexylene glycol and pinacol were prepared in excellent yields according to a simple, safe procedure. The metal-halogen exchange reaction between i PrMgCl 3 LiCl and aryl iodides is performed at 0 °C in the presence of a cyclic borate ester (MPBO i Pr or PinBO i Pr); the organomagnesium intermediate is immediately trapped in situ so that no accumulation of hazardous reactive species can occur. The reaction is very selective, and particularly clean crude products are obtained. The scope of the procedure and the tuning of reaction parameters are investigated.