A chiralsecondaryaminephosphoramide was developed and identified as a powerful catalyst for the Mukaiyama–Michael addition of fluorinatedenolsilylethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternarycarbonstereocenter bearing either a difluoroalkyl or monofluoroalkyl group.
The active complexes of chiral N,N′‐dioxide ligands with dysprosium and magnesium salts catalyze the hetero‐Diels–Alderreaction between 2‐aza‐3‐silyloxy‐butadienes and alkylidene oxindoles to selectively form 3,3′‐ and 3,4′‐piperidinoyl spirooxindoles, respectively, in very high yields and with excellent enantioselectivities. The exo‐selective asymmetric cycloaddition successfully regaled the construction
Asymmetric organocatalytic conjugate addition of dialkyl phosphites to N-unprotected isatylidene malononitriles: access to 3-phospho-2-oxindoles with chiral quaternary stereocenters
作者:Zhao-Min Liu、Nai-Kai Li、Xiao-Fei Huang、Bing Wu、Ning Li、Chun-Yuen Kwok、Yong Wang、Xing-Wang Wang
DOI:10.1016/j.tet.2014.02.023
日期:2014.4
established for the first time by using a simple bifunctional tertiary amine–thioureacatalyst. The corresponding adducts, 3-phospho-2-oxindoles, containing a chiral quaternary carbon center at the 3-position of the oxindole, were obtained in good to excellent yields (up to 98%) with moderate to excellent enantioselectivities (up to 95% ee). In addition, optically active 3,3′-disubstituted oxindoles bearing carboxylate
A Brønsted Acid-Primary Amine as a Synergistic Catalyst for Stereoselective Asymmetric Diels-Alder Reactions
作者:Dhevalapally B. Ramachary、P. Sreekanth Reddy、Kodambahalli S. Shruthi、R. Madhavachary、P. V. Govardhana Reddy
DOI:10.1002/ejoc.201601011
日期:2016.11
Herein, we present the Bronsted-acid-controlled, primary-amine-catalyzed stereoselective asymmetric synthesis of druglike six-membered spirooxindoles from simple aliphatic substrates through a Barbas [4+2]-cycloaddition reaction by using 2-aminobuta-1,3-diene catalysis under ambient conditions.
Zinc-Catalyzed Enantioselective [3 + 3] Annulation for Synthesis of Chiral Spiro[indoline-3,4′-thiopyrano[2,3-b]indole] Derivatives
作者:Tian-Tian Liu、Yu Chen、Guang-Jian Mei、Yuan-Zhao Hua、Shi-Kun Jia、Min-Can Wang
DOI:10.3390/molecules28031056
日期:——
dinuclear zinc-ProPhenol complex as a catalyst, an efficient and novel [3 + 3] annulation of indoline-2-thiones and isatylidene malononitriles has been successfully developed via the Brønsted base and Lewis acid cooperative activation model. This practical methodology gives access to a broad range of chiral spiro[indoline-3,4'-thiopyrano[2,3-b]indole] derivatives in good yields with excellent levels of enantioselectivities