Site-selective and regioselective Diels–Alder reaction of allenyl aryl ethers

Abstract

The site-selectivity and regioselectivity of Diels–Alder reactions of allenyl aryl ethers with cyclopentadiene and acrolein were studied. While cyclopentadiene (as an electron-rich diene) only reacted with the external double bond of allenyl aryl ethers to provide the site-selective normal electron demand Diels–Alder cycloadducts, acrolein (as an electron-deficient diene) reacted with the C1–C2 π bond of allenyl aryl ethers to provide the site- and regioselective hetero-Diels–Alder cycloadducts as exclusive products.