Dynamic kinetic resolution of hemiaminals with axially chiral twisted amides
摘要:
Dynamic kinetic resolution of N-acylhemiaminals was performed by enantioselective acylation of the hydroxy groups with chiral twisted amides. The stereoselectivity was reversed in the presence of 4-DMAP. The absolute configuration of the products was determined based on the sign of CD Cotton effects. (C) 2001 Elsevier Science Ltd. All rights reserved.
Cu/Fe Catalyzed Intermolecular Oxidative Amination of Benzylic C−H Bonds
作者:Cong Liu、Qi Zhang、Hongbo Li、Shuangxi Guo、Bin Xiao、Wei Deng、Lei Liu、Wei He
DOI:10.1002/chem.201600107
日期:2016.4.25
We report a Cu/Fe co‐catalyzed Ritter‐type C−H activation/amination reaction that allows efficient and selective intermolecular functionalization of benzylic C−H bonds. This new reaction is featured by simple reaction conditions, readily available reagents and general substrate scope, allowing facile synthesis of biologically interesting nitrogen containing heterocycles. The Cu and Fe salts were found
The enzymatic dynamic kinetic resolution of N-acylhemiaminals by various lipases, namely, lipase PS, lipase AK and lipase QL, has been investigated. The acetylation of racemic N-acylhemiaminals with lipases exclusively produced the (R)-enantiomers in enantiomerically pure form and quantitative yields. (C) 2003 Elsevier Science Ltd. All rights reserved.
Dynamic kinetic resolution of hemiaminals using a novel DMAP catalyst
作者:Shinji Yamada、Kaori Yamashita
DOI:10.1016/j.tetlet.2007.11.026
日期:2008.1
We describe the first catalytic dynamic kinetic resolution of hemiaminals mediated by an organocatalyst. A 0.1-1 mol % catalyst loading is effective for the dynamic kinetic resolution of hemiaminals to produce esters up to 88% ee in high yields. A 10 mol % catalyst loading resulted in a decreased selectivity, whereas the selectivity increased at 50 degrees C. The absolute configuration is assigned on the basis of the empirical Cotton effect rule. (C) 2007 Elsevier Ltd. All rights reserved.