The total synthesis of gelsedilam, which features a highly diastereoselective thiol conjugate addition-intramolecular aldol reaction to install the strained and caged [3.2.2] bridged ring system and highly efficient NiCl /NaBH -mediated four-step transformation in one-pot to construct its five-membered lactam ring is reported.
View Article and Find Full Text PDFA highly enantioselective 1,3-dipolar cycloaddition of imino esters with methyleneindolinones has been realized by using readily available thiourea-quaternary ammonium salts as phase-transfer catalysts, enabling efficient construction of a range of chiral spiro[pyrrolidin-3,3'-oxindoles] in good yields with excellent enantioselectivities under mild conditions.
View Article and Find Full Text PDFA highly enantioselective α-amination of 3-substituted oxindoles with azodicarboxylates catalyzed by amino acids-derived chiral phosphine catalysts is reported. The corresponding products containing a tetrasubstituted carbon center attached to a nitrogen atom at the C-3 position of the oxindole were obtained in high yields and with up to 98% ee.
View Article and Find Full Text PDFA Pd-catalyzed enantiospecific formal [3 + 2] cycloaddition between chiral aziridines and indoles has been developed. With this method, chiral pyrroloindolines in enantiomerically pure forms were constructed in high yields and diastereoselectivities under mild conditions.
View Article and Find Full Text PDFA combination of an amino acid derived chiral phosphine catalyst and methyl acrylate efficiently catalyzed the direct Mannich reaction of cyclic β-ketoesters and N-Boc-aldimines. The dual-reagent catalysis was presumed to function through the formation of a zwitterion, which catalyzed the reaction with excellent stereocontrol via a hydrogen-bonding assisted chiral ion-pair pathway.
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