Premium
Addition of Organometallic Reagents to Chiral N ‐Methoxylactams: Enantioselective Syntheses of Pyrrolidines and Piperidines
Author(s) -
Jäkel Mascha,
Qu Jianping,
Schnitzer Tobias,
Helmchen Günter
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201302735
Subject(s) - enantioselective synthesis , chemistry , allylic rearrangement , reagent , potassium cyanide , iridium , cyanide , metathesis , group 2 organometallic chemistry , organic chemistry , combinatorial chemistry , stereochemistry , catalysis , molecule , polymerization , polymer
Enantioselective iridium‐catalyzed allylic substitutions were used to prepare N‐ allyl hydroxamic acid derivatives that were suitable for ring‐closing metathesis, giving N‐ methoxylactams. Reactions of these derivatives with Grignard or organolithium compounds gave hemiaminals, which could be reduced diastereoselectively via acyliminium intermediates to give cis ‐piperidines or cis ‐pyrrolidines with substituents in the 2,6‐ or 2,5‐positions, respectively. In addition, compounds with a quaternary carbon center could be synthesized by corresponding reactions with potassium cyanide/AcOH. The procedures were applied in the syntheses of alkaloids (−)‐209D and (+)‐prosophylline.