Given the important role played by 2-hydroxybiaryls in organic, medicinal and materials chemistry, concise methods for the synthesis of this common motif are extremely valuable. In seeking to extend the synthetic chemists' lexicon in this regard, we have developed an expedient and general strategy for the ortho-arylation of phenols and naphthols using readily-available boronic acids. Our methodology relies on in situ generation of a uniquely reactive Bi(V) arylating agent from a benchstable Bi(III) precursor via telescoped B-to-Bi transmetallation and oxidation. By exploiting reactivity

Thei mproved synthesis of g-, d-a nd elactones using ad inuclear N-heterocyclic carbene (NHC)-gold(I) catalyst is reported. This solventfree process provides access to g-a nd d-lactones in high regio-and stereoselectivity.R eactions were performed at low catalyst loadings andw ithout the need for any additives.T he use of adigold pre-catalyst providesanew synthetic route to functionalised e-lactones,p oorly accessible using previous methodologies.

The synthetic versatility of thiophenols is offset by their air-sensitivity and foul odor. It is demonstrated that S-aryl isothiouronium salts can be used as precursors to thiyl radicals, extending the practical benefits of these air-stable, odorless salts from ionic to single electron manifolds. The isothiouronium salts are accessed via Ni-catalyzed cross-coupling of (hetero)aryl iodides and thiourea and are isolated as free-flowing solids following anion exchange. Judicious choice of a redox-innocent counteranion enables use of these convenient thiophenol surrogates in radical processes, as is exemplified by the synthesis of non-symmetrical diaryl thioethers via light-promoted S-arylation.

Die Titelaldehyde (II) bilden bei Behandlung mit Wasser in Gegenwart von Essigsäure bei Raumtemp. die Aryltetrahydrofurofuranolone (I) und in siedendem Methanol oder Ethanol die isomeren Ether (III).