The first Lewis acid catalyzed vinylogous Mukaiyama-type Mannich addition of 3-alkenyl-2-silyloxyindoles to in situ generated N-Boc imines has been established, which affords chiral α-alkylidene-δ-amino-2-oxindole products with good efficiency and complete γ-site- and Z-selectivity. The reaction is wide in scope, as it can be applied with equal convenience to different silyloxyindole donors and aromatic or aliphatic aminal-derived aldimine acceptors. The utility of these scaffolds is demonstrated by their easy transformation into either spirocyclopropane oxindole or homotryptaminelike products, featuring nontraditional indole-based skeleton connections.
3‑Alkenyl-2-silyloxyindoles in Vinylogous Mannich Reactions: Synthesis of Aminated Indole-Based Scaffolds and Products / Ranieri, Beatrice; Sartori, Andrea; Curti, Claudio; Battistini, Lucia; G., Rassu; Pelosi, Giorgio; Casiraghi, Giovanni; Zanardi, Franca. - In: ORGANIC LETTERS. - ISSN 1523-7060. - 16:(2014), pp. 932-935. [10.1021/ol4036598]
3‑Alkenyl-2-silyloxyindoles in Vinylogous Mannich Reactions: Synthesis of Aminated Indole-Based Scaffolds and Products.
RANIERI, Beatrice;SARTORI, Andrea;CURTI, Claudio;BATTISTINI, Lucia;PELOSI, Giorgio;CASIRAGHI, Giovanni;ZANARDI, Franca
2014-01-01
Abstract
The first Lewis acid catalyzed vinylogous Mukaiyama-type Mannich addition of 3-alkenyl-2-silyloxyindoles to in situ generated N-Boc imines has been established, which affords chiral α-alkylidene-δ-amino-2-oxindole products with good efficiency and complete γ-site- and Z-selectivity. The reaction is wide in scope, as it can be applied with equal convenience to different silyloxyindole donors and aromatic or aliphatic aminal-derived aldimine acceptors. The utility of these scaffolds is demonstrated by their easy transformation into either spirocyclopropane oxindole or homotryptaminelike products, featuring nontraditional indole-based skeleton connections.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
