A simple, direct, and highly enantioselective synthesis of spiro-oxindole piperidin-2-one derivatives was achieved through an aza-Michael/Michael cyclization cascade sequence using a squaramide catalyst. The desired products were obtained in excellent yields (up to 99%) and good to high stereoselectivities (up to >20:1 dr and up to 99% ee) under mild conditions.
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http://dx.doi.org/10.1021/acs.orglett.0c00779 | DOI Listing |
Org Lett
May 2020
Department of Chemistry, Fudan University, Shanghai 200433, China.
A simple, direct, and highly enantioselective synthesis of spiro-oxindole piperidin-2-one derivatives was achieved through an aza-Michael/Michael cyclization cascade sequence using a squaramide catalyst. The desired products were obtained in excellent yields (up to 99%) and good to high stereoselectivities (up to >20:1 dr and up to 99% ee) under mild conditions.
View Article and Find Full Text PDFOrg Lett
December 2017
School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
A newly developed SPD (spiro-pyrrolidine) organocatalyst has been demonstrated to enable an asymmetric aza-Michael/Michael/aldol cyclization cascade, in which two six-membered rings (B/C) and three stereocenters have been constructed in a catalytic one-step process. It is so far the most efficient method for construction of hydrophenanthridine derivatives featuring high enantioselectivity. The trans- or cis-fused B/C-rings can be selectively assembled in a substrate-controlled manner.
View Article and Find Full Text PDFChemistry
November 2014
Université Paris-Sud, UMR 8076 BioCIS, LabEx LERMIT, Equipe de Chimie des Substances naturelles 5, rue Jean-Baptiste Clément, 92296 Châtenay-Malabry (France).
Switchable tandem intramolecular aza-Michael/Michael and double aza-Michael reactions allow the oriented synthesis of highly functionalised cyclic skeletons. Conjugate addition of deactivated anilines triggers chemo- and stereo-divergent ring-closure reaction pathways with a striking selectivity depending on reaction conditions.
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