Davide Garanzini

A simple and efficient approach for the synthesis of 2-spirocyclopropyl-indolin-3-ones is herein described.

In this paper, we describe a new silver catalysed domino approach to 6‐substituted benzoxazino isoquinolines starting from 2‐alkynylbenzaldehydes and 1‐substituted‐(2‐aminophenyl)methanols. The strategy is characterized by good reaction yields, and can be performed at room temperature as well as under heating (conventional or dielectric) in different reaction times. Best results have been obtained by using silver complexes of macrocyclic pyridine‐containing ligands (PcL) as catalysts. The stereoselectivity of the transformation has been investigated by using chiral reaction partners and chiral catalysts, but unfortunately, modest stereoselectivities have been achieved. On the other hand, this approach represents an alternative synthetic strategy for the preparation of 6‐substituted benzoxazino isoquinolines, which are the key scaffold of some compounds endowed of biological activity.

In this paper, we describe the synthesis of neglected 1‐aminoisochromene derivatives starting from 2‐alkynylbenzaldehydes and electron‐poor anilines. The domino reaction is catalyzed by original [Ag^IPcL] complexes and occurs with complete regioselectivity under mild conditions. The approach well‐tolerates different aryl, heteroaryl, alkyl and cycloalkyl substituents on alkyne terminus to give the desired products in modest to very good yields.