A Simple, Modular Synthesis of Substituted Pyridines
作者:Songbai Liu、Lanny S. Liebeskind
DOI:10.1021/ja8013743
日期:2008.6.1
A simple, modular method to prepare highly substitutedpyridines is disclosed. The method employs a cascade reaction comprising (1) a novel N-iminative, Cu-catalyzed cross-coupling of alkenylboronic acids at the N-O bond of alpha,beta-unsaturated ketoxime O-pentafluorobenzoates, (2) electrocyclization of the resulting 3-azatriene, and (3) air oxidation affording highly substitutedpyridines in moderate
Highly Enantioselective and Efficient Organocatalytic Aldol Reaction of Acetone and β,γ-Unsaturated α-Keto Ester
作者:Pengfei Li、Junling Zhao、Fengbo Li、Albert S. C. Chan、Fuk Yee Kwong
DOI:10.1021/ol102254q
日期:2010.12.17
An effective organocatalytic asymmetric aldol reaction of acetone to β,γ-unsaturated α-keto ester has been developed. In the presence of 5 mol % of 9-amino (9-deoxy)-epicinchona alkaloid and 10 mol % of 4-nitrobenzoic acid, the aldol adducts containing a chiral tertiary alcohol moiety were obtained in excellent yields and enantioselectivities.
Diaryl Dihydropyrazole-3-carboxamides with Significant In Vivo Antiobesity Activity Related to CB1 Receptor Antagonism: Synthesis, Biological Evaluation, and Molecular Modeling in the Homology Model
作者:Brijesh Kumar Srivastava,*、Amit Joharapurkar、Saurin Raval、Jayendra Z. Patel、Rina Soni、Preeti Raval、Archana Gite、Amitgiri Goswami、Nisha Sadhwani、Neha Gandhi、Harilal Patel、Bhupendra Mishra、Manish Solanki、Bipin Pandey、Mukul R. Jain、Pankaj R. Patel
DOI:10.1021/jm061490u
日期:2007.11.1
A number of analogues of diaryl dihydropyrazole-3-carboxamides have been synthesized. Their activities were evaluated for appetite suppression and body weight reduction in animal models. Depending on the chemical modification of the selected dihydropyrazole scaffold, the lead compounds-the bisulfate salt,of (+/-)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-1H-pyrazole-3-carboxylic acid morpholin-4-ylamide 26 and the bisulfate salt of (-)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4,5-dihydro-1H-pyrazole3-carboxylic acid morpholin-4-ylamide 30-showed significant body weight reduction in vivo, which is attributed to their CB1 antagonistic activity and exhibited a favorable pharmacokinetic profile. The molecular modeling studies also showed interactions of two isomers of (+/-)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)4,5-dihydro- 1H-pyrazole-3-carboxylic acid morpholin-4-ylamide 9 with CB I receptor in the homology model similar to those of N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxarnide (rimonabant) 1 and 4S-(-)-3-(4-chlorophenyl)-N-methyl-N'-[(4-chlorophenyl)-sulfonyl]-4-pheny1-4,5-dihydro-1H-pyrazole-1-carboxamidine (SLV-319) 2.