The natural alkaloid isoanabasine: synthesis from 2,3′-bipyridine, efficient resolution with BINOL, and assignment of absolute configuration by Mosher’s method
摘要:
A highly efficient and practical resolution or racemic 1-benzyiisoanabasine, which was synthesized by reduction of the benzyl salt of 2,3'-bipyridine, has been achieved through molecular complexation with (R)-BINOL or (S)-BINOL to afford pure enantiomers (100% ee). The two enantiomers of the natural alkaloid isoanabasine have been obtained by debenzylation of the corresponding enantiomeric 1-benzylisoanabasine. Using Mosher's method by NMR techniques, the absolute configuration of (-)-isoanabasine has been assigned as the (R)-configuration for the first time. Moreover, an unexpected rotamer ratio of Mosher's amide was observed. The sYn-form of two rotamers of (R)-MTPA-(R)-isoanabasine was predominant over the anti-form. (c) 2005 Elsevier Ltd. All rights reserved.
The natural alkaloid isoanabasine: synthesis from 2,3′-bipyridine, efficient resolution with BINOL, and assignment of absolute configuration by Mosher’s method
摘要:
A highly efficient and practical resolution or racemic 1-benzyiisoanabasine, which was synthesized by reduction of the benzyl salt of 2,3'-bipyridine, has been achieved through molecular complexation with (R)-BINOL or (S)-BINOL to afford pure enantiomers (100% ee). The two enantiomers of the natural alkaloid isoanabasine have been obtained by debenzylation of the corresponding enantiomeric 1-benzylisoanabasine. Using Mosher's method by NMR techniques, the absolute configuration of (-)-isoanabasine has been assigned as the (R)-configuration for the first time. Moreover, an unexpected rotamer ratio of Mosher's amide was observed. The sYn-form of two rotamers of (R)-MTPA-(R)-isoanabasine was predominant over the anti-form. (c) 2005 Elsevier Ltd. All rights reserved.
Pyridyltetrahydropyridines and pyridylpiperidines and method of manufacturing them
申请人:Kuwabara Hirokazu
公开号:US20070093528A1
公开(公告)日:2007-04-26
The present invention provides pyridine derivatives useful as intermediates of drugs and agricultural chemicals, electrophotographic receptors, dyes and so on. More specifically, the invention relates to novel pyridyltetrahydropyridines and novel pyridylpiperidines, and further to a method of manufacturing pyridine derivatives through reaction between bipyridine derivatives and benzyl halide or benzyloxycarbonyl halide and subsequent reduction of the resultant reaction products with the aid of palladium catalysts, platinum catalysts, ruthenium catalysts or rhodium catalysts.
Pyridyltetrahydropyridines and Pyridylpiperidines, and Method of Manufacturing Them
申请人:Kuwabara Hirokazu
公开号:US20100029947A1
公开(公告)日:2010-02-04
The present invention provides pyridine derivatives useful as intermediates of drugs and agricultural chemicals, electrophotographic receptors, dyes and so on. More specifically, the invention relates to novel pyridyltetrahydropyridines and novel pyridylpiperidines, and further to a method of manufacturing pyridine derivatives through reaction between bipyridine derivatives and benzyl halide or benzyloxycarbonyl halide and subsequent reduction of the resultant reaction products with the aid of palladium catalysts, platinum catalysts, ruthenium catalysts or rhodium catalysts.
The natural alkaloid isoanabasine: synthesis from 2,3′-bipyridine, efficient resolution with BINOL, and assignment of absolute configuration by Mosher’s method
A highly efficient and practical resolution or racemic 1-benzyiisoanabasine, which was synthesized by reduction of the benzyl salt of 2,3'-bipyridine, has been achieved through molecular complexation with (R)-BINOL or (S)-BINOL to afford pure enantiomers (100% ee). The two enantiomers of the natural alkaloid isoanabasine have been obtained by debenzylation of the corresponding enantiomeric 1-benzylisoanabasine. Using Mosher's method by NMR techniques, the absolute configuration of (-)-isoanabasine has been assigned as the (R)-configuration for the first time. Moreover, an unexpected rotamer ratio of Mosher's amide was observed. The sYn-form of two rotamers of (R)-MTPA-(R)-isoanabasine was predominant over the anti-form. (c) 2005 Elsevier Ltd. All rights reserved.