Alpha,beta-unsaturated esters and acids by stereoselective dehydration
申请人:Deng Xiaohu
公开号:US20060004195A1
公开(公告)日:2006-01-05
There are provided by the present invention certain pyrazole based CCK-1 receptor modulators which have the general formula:
wherein Ar is an aromatic or heteroaromatic group, X is a hydrocarbon linker, Y is a bond or hydrocarbon linker and R
1
, R
2
, R
3
, R
4
and R
5
are certain organic substituents, methods for making the same, and stereoselective dehydration methods for generally making α,β-unsaturated esters, acids and their derivatives.
Efficient Trifluoromethylation of Activated and Non-Activated Alkenyl Halides by Using (Trifluoromethyl)trimethylsilane
作者:Andreas Hafner、Stefan Bräse
DOI:10.1002/adsc.201100528
日期:2011.11
An efficient method for the trifluoromethylation of halogenated double bonds by using in situ generated “trifluoromethyl copper” is described. Herein, the most common trifluoromethyl source, (trifluoromethyl)trimethylsilane, was converted selectively into “trifluoromethyl copper” by using copper iodide as copper source and potassium fluoride as promoter. In 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone
Efficient ligand-free palladium catalyzed Mizoroki–Heck reaction allowed the formation of trisubstituted α-trifluoromethylacrylates. The reaction showed good chemical tolerance and furnished moderate to excellent yields of reaction. Silver salt additive proved to be essential for the reaction. The reaction has been then applied to the formation of 3-trifluoromethyl coumarins and analogues of therapeutic
α-Trifluoromethylacrylates were synthesized using efficient ligand-free palladium catalyzed Mizoroki-Heckreaction. With the alkyl trifluoromethylacrylates used as substrates, different catalytic systems were explored including Pd/C as a catalyst. Good to excellent yields were obtained with good chemical tolerance
Transition metal-catalyzed formation of CF3-substituted α,β-unsaturated alkene and the synthesis of α-trifluoromethyl substituted β-amino ester
作者:Wan Pang、Shifa Zhu、Huanfeng jiang、Shizheng Zhu
DOI:10.1016/j.tet.2006.09.041
日期:2006.12
A new transition metal-catalyzed formation of CF3-substituted α,β-unsaturated alkenes through the ylide intermediate from the reaction between methyl 3,3,3-trifluoro-2-diazopropionate 1 and aryl aldehydes has been developed. Further transformation of the alkene affords the α-trifluoromethyl substituted β-aminoester, a valuable intermediate in the synthesis of fluorine-containing amino acids with potential