A (-)-sparteine-directed highly enantioselective synthesis of boroproline. Solid- and solution-state structure and properties.
A two-step, direct asymmetric synthesis of the trifluoroacetate ammonium salt of boroproline is reported. (-)-Sparteine-mediated lithiation of N-Boc-pyrrolidine afforded N-Boc-aminoboronic acid in good yield and enantioselectivity as determined by HPLC (pinanediol ester). Deprotection using TFA yielded the ammonium salt; full characterization data are presented, and the structure in aqueous solution and the occurrence of a B-N species are discussed.
Batsanov
Andrei S
AS
Chemistry Department, Durham University, Science Laboratories, South Road, Durham, U.K.
Grosjean
Christophe
C
Schütz
Thorben
T
Whiting
Andrew
A
D001895:Boron / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D011392:Proline / Q000737:chemistry*; D013034:Sparteine / Q000737:chemistry*; D013237:Stereoisomerism
D001896:Boron Compounds; D013034:Sparteine; D011392:Proline; D001895:Boron