Stereoselective synthesis of chiral 3,4,5-trisubstituted 1,5-dihydropyrrol-2-ones from azadienes
摘要:
A new access to enantiopure 3-phthalimido-4-amino-5-(1-hydroxyalkyl) 1,5-dihydropyrrol-2-ones has been developed from 1,3-azadienes. Stereoselective Lewis acid catalyzed addition of a cyano group to an azadiene, followed by intramolecular ring closure, in a four-step one-pot synthesis, results in the formation of gamma-lactams in satisfactory yields. (C) 1999 Elsevier Science Ltd. All rights reserved.
Microwave-assisted solvent-free organic reactions: Synthesis of β-lactams from 1,3-azadienes
摘要:
Ring-closure of 1,3-azadienes to beta-lactam rings is efficiently and quickly carried out under solvent-free conditions in an open-vessel microwave system. The synthesis of N-tert-butyldimethylsilyl azetidinones is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.
well as reaction conditions. Abinitiostudies at MP2/6−31G* and QCISD(T)/6−311G** levels on model compounds provide a rationalization of the experimental results obtained. From the experimental as well as theoretical data it is clear that the presence of the silyl enol group in the intermediate azadiene is crucial in its stabilisation and plays a fundamental role in the conrotatory ringclosure and,