Gold Salts as Alternative\nCatalysts in Promoting Cascade\nCondensation of 2‑Aminobenzaldehydes with Alcohols and Amines

The distinctive features of gold self-relay catalysts\nwere alternatively\nutilized in the intriguing cascade condensation of 2-aminobenzaldehydes\nwith alcohols and amines. Using NaAuCl<sub>4</sub>·2H<sub>2</sub>O as a catalyst, a range of 13-alkyloxy-7,11<i>b</i>-dihydro-6<i>H</i>,13<i>H</i>-6,12-[1,2]benzenoquinazolino[3,4-<i>a</i>]quinazoline derivatives was produced in good to high yields\nthrough A<sub>3</sub>B condensation of various 2-aminobenzaldehydes\nwith alcohols. By carefully choosing the reaction conditions, gold\ncatalysis also proved effective for A<sub>2</sub>B condensation with\nprimary aryl- and benzylamines, facilitating the synthesis of challenging\nMcGeachin bisaminals, including a chiral nonracemic derivative of\n2-(<i>S</i>)-methylbenzylamine. The mild conditions of this\ngold-catalyzed approach may lead to new advancements in the field.