6533b826fe1ef96bd12845ac

RESEARCH PRODUCT

ChemInform Abstract: Aza-Henry Reaction of Isatin Ketimines with Methyl 4-Nitrobutyrate en Route to Spiro[piperidine-3,3′-oxindoles].

Gonzalo BlayMelireth HolmquistJosé R. PedroM. Carmen Muñoz

subject

chemistry.chemical_compoundNitroaldol reactionchemistryAmino estersIsatinNitroEnantioselective synthesisGeneral MedicinePiperidineOximeMedicinal chemistryAdduct

description

A new enantioselective route to spiro[piperidine-3,3′-oxindoles] from isatin ketimines is described. The aza-Henry reaction of N-Boc-isatin ketimines with methyl 4-nitrobutyrate in the presence of a Ph2BOX-CuBr2 complex provided the corresponding nitro amino esters with good diastereoselectivity and excellent enantioselectivity (up to >99% ee). The aza-Henry adducts were transformed into spiro[piperidine-3,3′-oxindoles] after reduction of the nitro group to oxime, and cleavage of the N-Boc group and lactamisation.

https://doi.org/10.1002/chin.201617105