The influence of benzylic protection and allylic substituents on the CuCl-TMEDA catalyzed rearrangement of N-allyl-N-benzyl-2,2-dihaloamides to γ-lactams. Application to the stereoselective synthesis of pilolactam
摘要:
A number of N-benzylic protecting groups and allylic substituents have been investigated for the rearrangement, promoted by CuCl-TMEDA, of N-allyl-2,2-dihaloamides to 3,4-disubstituted gamma-lactams. An appreciable chiral induction was observed at the C-4 site when alpha-phenylethylamine was used as a chiral protecting group, while an unexpected Diels-Alder reaction occurred when using a 2-furyl-methyl protection. This rearrangement has been applied to the synthesis of pilolactam, a drug with muscarinic activity. (C) 1999 Elsevier Science Ltd. All rights reserved.
The influence of benzylic protection and allylic substituents on the CuCl-TMEDA catalyzed rearrangement of N-allyl-N-benzyl-2,2-dihaloamides to γ-lactams. Application to the stereoselective synthesis of pilolactam
作者:Franco Ghelfi、Franco Bellesia、Luca Forti、Gianluca Ghirardini、Romano Grandi、Emanuela Libertini、Maria C Montemaggi、Ugo M Pagnoni、Adriano Pinetti、Laurent De Buyck、Andrew F Parsons
DOI:10.1016/s0040-4020(99)00247-1
日期:1999.4
A number of N-benzylic protecting groups and allylic substituents have been investigated for the rearrangement, promoted by CuCl-TMEDA, of N-allyl-2,2-dihaloamides to 3,4-disubstituted gamma-lactams. An appreciable chiral induction was observed at the C-4 site when alpha-phenylethylamine was used as a chiral protecting group, while an unexpected Diels-Alder reaction occurred when using a 2-furyl-methyl protection. This rearrangement has been applied to the synthesis of pilolactam, a drug with muscarinic activity. (C) 1999 Elsevier Science Ltd. All rights reserved.
Efficient and Green Route to γ-Lactams by Copper-Catalysed Reversed Atom Transfer Radical Cyclisation of α-Polychloro-<i>N</i>-allylamides, using a Low Load of Metal (0.5 mol%)
作者:Franco Bellesia、Andrew J. Clark、Fulvia Felluga、Armando Gennaro、Abdirisak A. Isse、Fabrizio Roncaglia、Franco Ghelfi
DOI:10.1002/adsc.201300132
日期:2013.5.17
The cyclisation of N‐allyl‐N‐substituted‐α‐polychloroamides is efficiently obtained through a copper‐catalysed activators regenerated by electron transfer–atom transferradicalcyclisation process, with a metalload of only 0.5mol%. The redox catalyst is introduced in its inactive form as copper(II) chloride/[nitrogen ligand] complex, and continuously regenerated to the active copper(I) chloride/[nitrogen