Synthesis of substituted benzooxaborinin-1-ols via palladium-catalysed cyclisation of alkenyl- and alkynyl-boronic acids

Two new palladium-catalysed reactions have been developed for the synthesis of stable 4-substituted benzooxaborinin-1-ols. A palladium-catalysed cyclisation of ortho-alkenylbenzene boronic acids can be used to access 4-chlorobenzooxaborinin-1-ols via a Wacker-type oxidation and chlorination. Alternatively, ortho-alkynylbenzene boronic acids undergo a palladium-catalysed oxyallylation reaction to provide 4-allylbenzooxaborinin-1-ols

Sonochemical synthesis of nano-cocrystals

Cocrystals are multicomponent solids with organic molecules assembled in combination to form a crystalline solid with properties different than the individual components. A cocrystal typically consists of a target molecule crystallized with a second molecule, or cocrystal former, employed to influence properties of the target (e.g. solubility). The conformer interacts with the target via intermolecular forces (e.g. hydrogen bonds) that hold the components together. The modularity of a cocrystal makes such solids attractive for applications where fine-tuning of properties is important (e.g. optical). In this presentation, we describe the use of sonochemistry to form cocrystals of nanoscale dimensions. In contrast to single-component solids, cocrystals present a fundamentally different challenge with respect to those reprecipitation methods used to form nanocrystals since the components of a cocrystal will tend to exhibit different solubilities. We show that sonochemistry affords nano-cocrystals with properties (e.g. reactivity) that contrast solids of macroscale dimensions. Related applications of sonochemistry to afford singlecomponent nanocrystals will also be presented. © 2013 Acoustical Society of America