Stereoselective Synthesis of 2-Substituted Pyrrolidines

2000 ◽  
Vol 65 (5) ◽  
pp. 816-828 ◽  
Author(s):  
Sandrine Deloisy ◽  
Heiko Tietgen ◽  
Horst Kunz
Keyword(s):  
Stereoselective Synthesis ◽  
Diastereomeric Purity

Using O-pivaloyl protected D-galactopyranosylamine and D-arabinopyranosylamine, (S) or (R) configured α-substituted homoallylamines are synthesized with high diastereoselectivity by reaction of the corresponding aldimines with allyltributylstannane. Electrophile-induced endo-trig-cyclization of these N-glycosylhomoallylamines gave the 2-substituted pyrrolidines of high diastereomeric purity.

Selective synthesis of E-isomers of aldoximes via a domino aza-Michael/retro-Michael reaction

2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Wei Chen ◽  
Wei-Guo Yu ◽  
Hai-Bo Shi ◽  
Xiao-Yan Lu
Keyword(s):  
1H Nmr ◽  
Room Temperature ◽  
Stereoselective Synthesis ◽  
Michael Reaction ◽  
Selective Synthesis ◽  
Reaction Conditions ◽  
High Yields ◽  
Diastereomeric Purity ◽  
Benzylidene Malononitrile

AbstractA highly stereoselective synthesis of E-isomer of aldoximes was developed through a base-catalysed domino aza-Michael/retro-Michael reaction of hydroxylamine and 2-(R-benzylidene)malononitrile. This reaction generates (E)-aldoxime diastereomer in high yields (eight examples, isolated yields of 82-93 %), excellent diastereomeric purity (diastereomeric ratio higher than 95: 5 by 1H NMR), and proceeds under mild reaction conditions (aqueous NaOH, pH 12, room temperature, 4 h).

Stereoselective Synthesis 1 Stereoselective Reactions of Carbon—Carbon Double Bonds

2011 ◽  
Author(s):  
J. G. de Vries ◽  
K. Muñiz ◽  
G. Franciò ◽  
W. Leitner ◽  
P. L. Alsters ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Double Bonds ◽  
Stereoselective Reactions

Enantioselective Multi-Component Cyclopropane Synthesis Enabled by Cu-Catalyzed Cyclopropene Carbometallation with Organoboron Reagent

2018 ◽  
Author(s):  
Zhanyu Li ◽  
Mengru Zhang ◽  
Yu Zhang ◽  
Shuang Liu ◽  
Jinbo Zhao ◽  
...  
Keyword(s):  
Carbon Source ◽  
Stereoselective Synthesis ◽  
Organometallic Reagents ◽  
Preliminary Results ◽  
Quaternary Center ◽  
Chiral Centers ◽  
Substituted Cyclopropanes ◽  
Proof Of Principle

Deployment of organoboron in lieu of the strongly basic <br>organometallic reagents as carbon source in Cu-catalyzed <br>cyclopropene carbometallation opens unprecedented three-<br>component reactivity for stereoselective synthesis of poly-substituted cyclopropanes. A proof-of-principle demonstration of this novel carbometallation strategy is presented herein for a highly convergent access to poly-substituted aminocyclopropane framework via <br>carboamination. Preliminary results on asymmetric desymmetrization with commercial bisphosphine ligands attained high levels of enantioselection, offering a straightforward access to enantioenriched aminocyclopropanes bearing all-three chiral centers, including an all-carbon quaternary center. This strategy may underpin a host of novel synthetic protocols for poly-substituted cyclopropanes. <br>

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