A Concise Enantioselective Synthesis of Fluorinated Pyrazolo-Piperidine GSK3901383A Enabled by an Organocatalytic
Benedict Barron1, Colin Edge2, Sabine Fenner1
1Drug Substance Development, GSK, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K.
Abstract:
A highly enantioselective organocatalytic aza-Michael addition of 4-nitro-pyrazole to ethyl (E)-2,2-difluoro-5-oxopent-3-enoate has been developed. This reaction enabled a concise, four-step, stereoselective synthesis of highly functionalized 3,3-difluoro-4-pyrazolo-piperidine GSK3901383A, a key intermediate for the synthesis of a leucine-rich repeat kinase 2 inhibitor API. Computational analysis provided insight into the steric requirements of the catalytic system, enabling rational selection of a highly selective catalyst.
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