Organocatalytic Stereoselective Synthesis of Acyclic γ-Nitrothioesters with All-Carbon Quaternary Stereogenic Centers

2014 ◽  
Vol 79 (9) ◽  
pp. 3937-3945 ◽  
Author(s):  
Yukihiro Arakawa ◽  
Sven P. Fritz ◽  
Helma Wennemers
Keyword(s):  
Stereoselective Synthesis ◽  
Stereogenic Centers ◽  
Quaternary Stereogenic Centers

scholarly journals Lewis acid–catalyzed domino generation/[2,3]-sigmatropic rearrangement of ammonium ylides to access chiral azabicycles

2021 ◽  
Vol 7 (5) ◽  
pp. eabd5290
Author(s):  
Song Xi ◽  
Jiawei Dong ◽  
Haohua Chen ◽  
Qiuyan Dong ◽  
Jiao Yang ◽  
...  
Keyword(s):  
Density Functional ◽  
Stereoselective Synthesis ◽  
Experimental Studies ◽  
Reaction System ◽  
Density Functional Theory Calculations ◽  
Sigmatropic Rearrangement ◽  
Residual Water ◽  
Nitrogenous Compounds ◽  
Stereogenic Centers ◽  
Quaternary Stereogenic Centers

[2,3]-Sigmatropic rearrangement of ammonium ylides represents a fundamental reaction for stereoselective synthesis of nitrogenous compounds. However, its applicability is limited by the scarcity of efficient, catalytic, and mild methods for generating ammonium ylides. Here, we report silver-catalyzed domino generation/[2,3]-sigmatropic rearrangement of ammonium ylides, furnishing chiral azabicycles with bridgehead quaternary stereogenic centers in high enantiomeric purity (up to 99% ee). A combination of density functional theory calculations and experimental studies revealed that residual water in the reaction system is crucial for the mild reaction conditions by functioning as a proton shuttle to assist carbon-silver bond protonation and C2─H deprotonation to generate the ammonium ylide. This reaction has a broad application scope. Besides the diverse substituents, N-fused azabicycles of various ring sizes are also easily accessed. In addition to silver salts, this strategy has also been successfully implemented by using a stoichiometric amount of nonmetallic I2.

All-Carbon Quaternary Stereogenic Centers in Acyclic Systems through the Creation of Several C–C Bonds per Chemical Step

2014 ◽  
Vol 136 (7) ◽  
pp. 2682-2694 ◽  
Author(s):  
Ilan Marek ◽  
Yury Minko ◽  
Morgane Pasco ◽  
Tom Mejuch ◽  
Noga Gilboa ◽  
...  
Keyword(s):  
Stereogenic Centers ◽  
The Creation ◽  
Quaternary Stereogenic Centers
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