Premium
On‐Water Vinylogous Mukaiyama–Michael Addition of Heterocyclic 2‐Silyloxydienes to 1,2‐Diaza‐1,3‐dienes: One‐Pot Three‐Step Entry to Functionality‐Rich Pyrroles
Author(s) -
Battistini Lucia,
Dell'Amico Luca,
Sartori Andrea,
Curti Claudio,
Pelosi Giorgio,
Casiraghi Giovanni,
Attanasi Orazio A.,
Favi Gianfranco,
Zanardi Franca
Publication year - 2011
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201100296
Subject(s) - chemistry , michael reaction , aromatization , intramolecular force , pyrrole , stereoselectivity , lewis acids and bases , catalysis , organic chemistry , aqueous solution , one pot synthesis , combinatorial chemistry
Densely substituted pyrrole‐carboxylates have been prepared in good yields in a highly practical one‐pot three‐step procedure. The key reaction of this process, which involves an uninterrupted sequence of reactions on‐water, is a diastereoselective vinylogous Mukaiyama–Michael addition reaction (VMMcR) of heterocyclic 2‐silyloxydienes to 1,2‐diaza‐1,3‐dienes mediated by water itself. Subsequent in situ addition of catalytic aqueous sodium carbonate promotes an intramolecular aza‐Michael addition with final ring‐opening and aromatization. The superior use of water in the VMMcR as both reaction medium and promoter vis‐à‐vis deployment of conventional Lewis acids in organic solvents is highlighted, which provides the best results in terms of reaction rate, efficiency, stereoselectivity, and overall practicality.