Highly Enantioselective Friedel−Crafts Reaction of Indoles with 2-EnoylPyridine 1-Oxides Catalyzed by Chiral Pyridine 2,6-Bis(5′,5′-diphenyloxazoline)−Cu(II) Complexes
作者:Pradeep K. Singh、Vinod K. Singh
DOI:10.1021/ol8016929
日期:2008.9.18
The catalytic enantioselective Friedel-Crafts reaction of indoles with 2-enoylpyridine 1-oxides has been studied in the presence of chiral pyridine 2,6-bis(5',5'-diphenyloxazoline)-Cu(II) complexes. The reaction furnished alkylated indoles in excellent yields (up to 97%) and enantioselectivities (up to 99% ee).
Enantioselective Michael Addition of Malonates to 2-Enoylpyridine <i>N</i>-Oxides Catalyzed by Chiral Bisoxazoline–Zn(II) Complex
作者:Sumit K. Ray、Pradeep K. Singh、Vinod K. Singh
DOI:10.1021/ol202405v
日期:2011.11.4
An enantioselective Michael addition of malonates to 2-enoylpyridine N-oxides catalyzed by a chiral bisoxazoline–Zn(II) complex has been developed. The corresponding Michael adducts have been obtained in high yields with up to 96% ee. A plausible transition-state model has been proposed to explain the stereochemical outcome of the reaction.
Organocatalytic Enantioselective Michael Addition of Oxazolones to 2‐Enoylpyridine
<i>N</i>
‐Oxides for Assembling of Pyridine
<i>N</i>
‐Oxides Featuring Vicinal Oxygen‐Containing Tetrasubstituted Stereocenters
作者:Yipeng Luan、Anqi Huang、Yuyu Cheng、Xiaohong Liu、Pengfei Li、Wenjun Li
DOI:10.1002/adsc.201900684
日期:2019.9.17
enantioselective Michael addition of 5H‐oxazol‐4‐ones to 2‐enoylpyridine N‐oxides is described. Under mild conditions, a series of optically active pyridine N‐oxides inlaid with oxazolone motif were obtained in high yields (62–99%) with excellent stereoselectivities (84–>99% ee and >20:1 dr). Notably, the method offers a direct synthetic approach to enantioenriched pyridine N‐oxides featured by vicinal
Copper(II)-catalyzed enantioselective conjugate addition of nitro esters to 2-enoyl-pyridine N-oxides
作者:Jianan Sun、Yanan Li、Yang Gui、Youguo Xu、Zhenggen Zha、Zhiyong Wang
DOI:10.1016/j.cclet.2018.11.024
日期:2019.3
enantioselective Michael addition of nitro esters to 2-enoyl-pyridine N-oxides was developed by using chiral copper catalysts. The Michael addition products can be obtained in high yields and with up to 96% ee. Moreover, asymmetric Michael addition product of nitromethane to 2-enoyl-pyridine N-oxides can be obtained in one step. An analogue of nicotine, dihydro-2H-pyrrol 4b was synthesized with this developed