Straightforward Access to Isoindoles and 1,2-Dihydrophthalazines Enabled by a Gold-Catalyzed Three-Component Reaction

We describe herein a gold-catalyzed three-component reaction of o-alkynylbenzaldehydes, aryldiazonium salts, and trimethoxybenzene. This process enables the one-pot formation of valuable isoindoles and 1,2-dihydrophathalazines. The regioselectivity of the reaction is dictated by the nature of the aryldiazonium salt. Noticeably, the reaction is performed at room temperature under mild conditions and tolerates a variety of functional groups on both the o-alkynylbenzaldehyde and the aryldiazonium salt. Experimental mechanistic studies suggest that it is catalyzed by arylAu(III) species.

Utilization of ortho-alkynylarylcarbonyl derivatives for creating structurally diverse chemical compounds

ortho-Alkynylarylcarbonyl compounds, including ketones, aldehydes, carboxylic acids, carboxylate esters and amides, have served as useful building blocks for synthetic chemists to prepare numerous classes of important molecules. Various synthetic conversions starting from ortho-alkynylarylcarbonyl precursors are made possible by their unique and enabling structures embedded with reactive carbonyl and alkyne functional groups. These functional groups can be converted directly and independently to other compounds by several reactions. This review highlights the use of these compounds as common precursors for the divergent synthesis of valuable molecules. Moreover, these ortho-alkynylarylcarbonyl compounds can be decorated with other functional group tethers which can lead to an even greater diversity of molecular scaffolds.