324750-04-1Relevant articles and documents
Catalytic Asymmetric Synthesis of Morpholines. Using Mechanistic Insights to Realize the Enantioselective Synthesis of Piperazines
Lau, Ying Yin,Zhai, Huimin,Schafer, Laurel L.
, p. 8696 - 8709 (2016/10/14)
An efficient and practical catalytic approach for the enantioselective synthesis of 3-substituted morpholines through a tandem sequential one-pot reaction employing both hydroamination and asymmetric transfer hydrogenation reactions is described. Starting from ether-containing aminoalkyne substrates, a commercially available bis(amidate)bis(amido)Ti catalyst is utilized to yield a cyclic imine that is subsequently reduced using the Noyori-Ikariya catalyst, RuCl [(S,S)-Ts-DPEN] (η6-p-cymene), to afford chiral 3-substituted morpholines in good yield and enantiomeric excesses of >95%. A wide range of functional groups is tolerated. Substrate scope investigations suggest that hydrogen-bonding interactions between the oxygen in the backbone of the ether-containing substrate and the [(S,S)-Ts-DPEN] ligand of the Ru catalyst are crucial for obtaining high ee's. This insight led to a mechanistic proposal that predicts the observed absolute stereochemistry. Most importantly, this mechanistic insight allowed for the extension of this strategy to include N as an alternative hydrogen bond acceptor that could be incorporated into the substrate. Thus, the catalytic, enantioselective synthesis of 3-substituted piperazines is also demonstrated.
Novel Compounds
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Page/Page column 20, (2008/12/04)
The invention relates to substituted aryl acids as useful pharmaceutical compounds for treating respiratory disorders, pharmaceutical compositions containing them, and processes for their preparation.
PIPERAZINE UREA DERIVATIVES AS MELANOCORTIN-4 RECEPTOR AGONISTS
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Page 80, (2010/11/30)
Certain novel piperazine urea derivatives are agonists of the human melanocortin-4 receptor (MC-4R) and, in particular, are receptor-subtype selective agonists of MC-4R. They are useful for the treatment, control, or prevention of diseases and disorders r
