74650-57-0Relevant articles and documents
γ- and δ-lactams through palladium-catalyzed intramolecular allylic alkylation: Enantioselective synthesis, NMR investigation, and DFT rationalization
Bantreil, Xavier,Prestat, Guillaume,Moreno, Aitor,Madec, David,Fristrup, Peter,Norrby, Per-Ola,Pregosin, Paul S.,Poli, Giovanni
supporting information; experimental part, p. 2885 - 2896 (2011/04/24)
The Pd-catalyzed intramolecular allylic alkylation of unsaturated amides to give γ- and δ-lactams has been studied in the presence of chiral ligands. Ligand (R)-3,5-tBu-MeOBIPHEP (MeOBIPHEP=6,6'-dimethoxybiphenyl-2,2- diyl)bis(diphenylphosphine)) afforded the best results and allowed the cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd-allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the processes responsible for the observed enantiomeric ratios. DFT studies were used to characterize the diastereomeric reaction pathways. The calculated energy differences were in good agreement with the experimentally observed enantiomeric ratios. A transient existence: The Pd-catalyzed intramolecular allylic alkylation of unsaturated amides to give γ- and δ-lactams in the presence of (R)-3,5-tBu-MeOBIPHEP takes place in up to 94:6 enantiomeric ratio (e.r.; see scheme). The energies of the diastereomeric transition states are in good agreement with the experimentally observed enantiomeric ratios.
Synthesis and Absolute Configuration of 3-Ethyl and 3-n-Propylpyrrolidine
Bettoni, Giancarlo,Cellucci, Carla,Berardi, Francesco
, p. 603 - 605 (2007/10/02)
Optically active 3-ethyl and 3-n-propylpyrrolidine were prepared by two independent routes from their corresponding succinic acids and the absolute configurations were assigned.Maximum optical rotation was also established through evaluation of the degree of racemization of the products obtained via both synthetic routes.
