Highly efficient 4-phenoxy substituted organocatalysts derived from N-prolylsulfonamide for the asymmetric direct aldol reaction on water

2009 ◽  
Vol 10 (4) ◽  
pp. 401-405 ◽  
Author(s):  
Shu-peng Zhang ◽  
Xiang-kai Fu ◽  
Shao-dong Fu ◽  
Jun-feng Pan
2019 ◽  
Vol 6 (2) ◽  
pp. 171-176
Author(s):  
Rajasekhar Dodda ◽  
Sampak Samanta ◽  
Matthew Su ◽  
John Cong-Gui Zhao

Background: While proline can catalyze the asymmetric direct aldol reactions, its catalytic activity and catalyst turnover are both low. To improve the catalytic efficiency, many prolinebased organocatalysts have been developed. In this regard, prolinamide-based bifunctional catalysts have been demonstrated by us and others to be highly efficient catalysts for the direct aldol reactions. Results: Using the β-acetamido- and β-tosylamidoprolinamide catalysts, the highly enantio- and diastereoselective direct aldol reactions between enolizable ketones and aldehydes were achieved (up to >99% ee, 98:2 dr). A low catalyst loading of only 2-5 mol % of the β-tosylamidoprolinamide catalyst was needed to obtain the desired aldol products in good to high yields and high stereoselectivities. Methods: By carefully adjusting the hydrogen bonding ability of the remote β-amide hydrogen of the 1,2-diamine-based prolinamide bifunctional catalysts, the catalytic activity and the asymmetric induction of these catalysts were significantly improved for the direct aldol reaction between aldehydes and enolizable ketones. Conclusion: Some highly efficient 1,2-diamine-based bifunctional prolinamide catalysts have been developed through probing the remote β-amide hydrogen for its hydrogen bonding capability. These catalysts are easy to synthesize and high enantioselectivities may be achieved at very low catalyst loadings.


RSC Advances ◽  
2013 ◽  
Vol 3 (12) ◽  
pp. 3861 ◽  
Author(s):  
Noureddine Khiar ◽  
Raquel Navas ◽  
Eleonora Elhalem ◽  
Victoria Valdivia ◽  
Inmaculada Fernández

2005 ◽  
Vol 7 (23) ◽  
pp. 5321-5323 ◽  
Author(s):  
Sampak Samanta ◽  
Jinyun Liu ◽  
Rajasekhar Dodda ◽  
Cong-Gui Zhao

2006 ◽  
Vol 8 (20) ◽  
pp. 4417-4420 ◽  
Author(s):  
Yongyong Wu ◽  
Yazhu Zhang ◽  
Menglong Yu ◽  
Gang Zhao ◽  
Shaowu Wang

2018 ◽  
Vol 29 (1) ◽  
pp. 194-196 ◽  
Author(s):  
Weipeng Qi ◽  
Xiaoqiang Xie ◽  
Tengjiang Zhong ◽  
Xingxian Zhang

Sign in / Sign up

Export Citation Format

Share Document