Synthesis of 1H-Isochromenes and 1,2-Dihydroisoquinolines by Indium(III)-Catalyzed Cycloisomerization of ortho-(Alkynyl)benzyl Derivatives

Autor: José Pérez Sestelo, Luis A. Sarandeses, Fabio Seoane-Carabel, Lorena Alonso-Marañón
Rok vydání: 2022
Předmět:
Zdroj: Synthesis. 55:1714-1723
ISSN: 1437-210X
0039-7881
DOI: 10.1055/s-0042-1751383
Popis: 1H-Isochromenes and 1,2-dihydroisoquinolines are synthesized by regioselective indium(III)-catalyzed intramolecular hydrofunctionalization of o-(alkynyl)benzyl derivatives. The reaction with o-(alkynyl)benzyl alcohols and amines proceeds using indium triiodide (5–10 mol%) in toluene at 80–100 °C via regioselective 6-endo-dig intramolecular alkyne hydroalkoxylation or hydroamination in good yields. Alternatively, the cycloisomerization reaction of o-(alkynyl)benzaldehydes and imine derivatives using InI3 (5 mol%) and the Hantzsch ester (120 mol%) takes place, under milder reaction conditions, to give a variety of functionalized 1H-isochromenes and 1,2-dihydroisoquinolines through a domino cycloisomerization/reduction approach.
Databáze: OpenAIRE