Asymmetric Direct Aldol Reaction of Functionalized Ketones Catalyzed by Amine Organocatalysts Based on Bispidine
作者:Jie Liu、Zhigang Yang、Zhen Wang、Fei Wang、Xiaohong Chen、Xiaohua Liu、Xiaoming Feng、Zhishan Su、Changwei Hu
DOI:10.1021/ja800839w
日期:2008.4.1
Organocatalysts containing primary-secondary aminebased on bispidine and amino acid have been designed to catalyze the asymmetric direct aldol reaction of functionalized ketones including alpha-keto phosphonates, alpha-keto esters, as well as alpha,alpha-dialkoxy ketones as aldol reaction acceptors. The corresponding products with chiral tertiary alcohols were obtained in moderate to high yields (up
Highly diastereoselective vinylogous Mukaiyama aldol reaction of α-keto phosphonates with 2-(trimethylsilyloxy)furan catalyzed by Cu(OTf)2
作者:Jipan Yu、Xiaona Zhao、Zhiwei Miao、Ruyu Chen
DOI:10.1039/c1ob05822c
日期:——
achieved via a vinylogous Mukaiyamaaldolreaction. The reaction was performed using α-ketophosphonate 1 and 2-(trimethylsilyloxy)furan 2 mediated by Cu(OTf)2 and 2,2,2-trifluoroethanol as additive in CH2Cl2. The reaction proceeds rapidly and affords the corresponding 5-(hydroxy(aryl)methyl) furan-2(5H)-one phosphonates 3 in high yields with good to excellent diastereoselectivities (d.r. up to >99 : 1)
Studies on Organophosphorus Compounds, 53: A New Procedure for the Synthesis of 1-Alkyl or 1-Aryl-1-hydroxy-2-nitroethylphoshonates under PTC Conditions
A series of dialkyl 1-alkyl- or 1-aryl-1-hydroxy-2-nitroethyl-phosphonates and 1-hydroxy-1-(nitromethyl)alkylphosphonates was prepared by nucleophilic addition of nitromethane to dialkyl acylphosphonates in the presence of potassium carbonate and tetrabutylammonium bromide.
yielding access to phosphonic γ‐(hydroxyalkyl)butenolides with excellent regio‐, diastereo‐ and enantiocontrol is reported. The simultaneous construction of up to two adjacent quaternary stereogenic centers by a catalytic asymmetric vinylogousMukaiyamaaldolreaction unites biologically and medicinally relevant entities, namely α‐hydroxy phosphonates and γ‐(hydroxyalkyl)butenolides. This is achieved by
Enantio- and Diastereoselective Vinylogous Mukaiyama Aldol Reactions of α-Keto Phosphonates with 2-(Trimethylsilyloxy)- furan Catalyzed by Bis(oxazoline)-Copper Complexes
The asymmetric vinylogousMukaiyamaaldolreaction between α-keto phosphonate and 2-(trimethylsilyloxy)furan was performed by using bis(oxazoline)-copper complexes as the catalyst and 2,2,2-trifluoroethanol as additive in dichloromethane. The present method is highly tolerable for functionalized α-keto phosphonates and enabled us to obtain the corresponding 3- and 4-substituted benzyl-functionalized