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Updated: Jul 13, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
A (-)-sparteine-directed highly enantioselective synthesis of boroproline. Solid- and solution-state structure and
Andrei S Batsanov1, Christophe Grosjean, Thorben Schütz
1Chemistry Department, Durham University, Science Laboratories, South Road, Durham, U.K.
Abstract:
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.
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