A catalyst-free, environmentally benign three-component vinylogous Mukaiyama–Mannich reaction of pyrrole-based silyl dienolates is presented, which works effectively in both aqueous and solvent-free environments. Both lipophilic and hydrophilic aldehyde candidates are suitable substrates, allowing access to a rich repertoire of unsaturated vicinal aminolactam structures with virtually complete γ-site selectivity and moderate to good anti-diastereoselectivity. The utility of this technology is highlighted by protecting group-free synthesis of densely hydroxylated, sugar-related lactam frameworks. The role of water as an indispensable H-bonding reaction propeller is demonstrated.
Aqueous and Solvent-Free Uncatalyzed Three-Component Vinylogous Mukaiyama-Mannich Reactions of Pyrrole-Based Silyl Dienolates / Sartori, Andrea; Dell'Amico, L.; Curti, Claudio; Battistini, Lucia; Pelosi, Giorgio; Rassu, G.; Casiraghi, Giovanni; Zanardi, Franca. - In: ADVANCED SYNTHESIS & CATALYSIS. - ISSN 1615-4150. - 353:(2011), pp. 3278-3284. [10.1002/adsc.201100572]
Aqueous and Solvent-Free Uncatalyzed Three-Component Vinylogous Mukaiyama-Mannich Reactions of Pyrrole-Based Silyl Dienolates
SARTORI, Andrea;CURTI, Claudio;BATTISTINI, Lucia;PELOSI, Giorgio;CASIRAGHI, Giovanni;ZANARDI, Franca
2011-01-01
Abstract
A catalyst-free, environmentally benign three-component vinylogous Mukaiyama–Mannich reaction of pyrrole-based silyl dienolates is presented, which works effectively in both aqueous and solvent-free environments. Both lipophilic and hydrophilic aldehyde candidates are suitable substrates, allowing access to a rich repertoire of unsaturated vicinal aminolactam structures with virtually complete γ-site selectivity and moderate to good anti-diastereoselectivity. The utility of this technology is highlighted by protecting group-free synthesis of densely hydroxylated, sugar-related lactam frameworks. The role of water as an indispensable H-bonding reaction propeller is demonstrated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.