An ultrasound-assisted one-pot acylation/cyclization reaction between N-acylbenzotriazoles and 2-hydroxybenzaldehydes has been developed for the synthesis of substituted 3-arylcoumarins. Using ultrasound not only allows rapid and clean conversion but also simplifies experimental setup and parallel workup leading to rapid generation of 3-arylcoumarin libraries under mild, solvent-free, and chromatography-free
Ph3P/I2–Et3N-mediated one-pot two-step esterification–cyclization toward 3-aryl coumarins and 3-aryl-4-methylcoumarins is reported. The reaction of a variety of aryl acetic acids containing steric or reactive group with 2-hydroxybenzaldehydes or 2′-hydroxyacetophenone proceeded smoothly at room temperature to afford the corresponding products in good to excellent yields using inexpensive and readily