Synthesis of functionalized 1-aminoisoquinolines through cascade three-component reaction of ortho-alkynylbenzaldoximes, 2H-azirines, and electrophiles.

We have developed a new three-component approach using ortho-alkynylbenzaldoximes involving the formation of a cyclic nitrone in the presence of Br2 or ICl for the synthesis of 1-aminoisoquinolines via cascade 6-endo-cyclization, 1,3-dipolar cycloaddition reaction with 2H-azirines, and ring-opening reaction sequences. The broad range of structurally diverse products, good to high yields, high atom-economy and high bond-formation efficiency make this method an attractive alternative for the synthesis of 1-aminoisoquinolines.