A TfOH‐Catalyzed Multicomponent Reaction of Propargylic Alcohols, Sulfonamides and Aldehydes for the Synthesis of Acyclic α‐Arylidene β‐Aminoketones

Abstract

This work demonstrates a TfOH‐catalyzed multicomponent reaction. Using propargylic alcohols, aldehydes and sulfonamides as the substrates, a wide variety of acyclic α‐arylidene β‐aminoketones were prepared in high yields. The reaction mechanism likely involved a sulfonyl imide intercepted Meyer‐Schuster rearrangement combined with 1,3‐aryl migration. The present transformations proceeded with a low catalyst loading and permitted a large number of substituents on all reactants. The superior atom economy, high yield and convenient operation of this reaction suggest that it may be a practical alternative for the construction of acyclic α‐arylidene β‐aminoketones.

Recent Progress in Application of Propargylic Alcohols in Organic Syntheses

“…In 2023, Yin and co‐workers reported a multi‐component approach for the preparation of acyclic α‐arylidene β‐aminoketones 168 starting from primary propargylic alcohols 1′′ , sulfonamides 166 and aromatic aldehydes 167 (Scheme 72). [67] In this reaction, TfOH was used as a Brønsted acid catalyst. In all products, E ‐isomer was preferred to Z ‐isomer due to the steric effect of substituents.…”