Thieny/Furanyl-hydroxyphenylpropenones as Inhibitors of LPS-induced ROS and NO Production in RAW 264.7 Macrophages, and Their Structure-Activity Relationship Study
Chiral aldehyde catalysis is uniquely suitable for the direct asymmetric α-functionalization of N-unprotected amino acids, because aldehydes can reversibly form imines. However, there have been few successful reports of these transformations. In fact, only chiral aldehyde catalyzed aldol reactions of amino acids and alkylation of 2-amino malonates have been reported with good chiral induction. Here
Y(OTf)3, were essential to promote the 1,4-addition of alkyl-substituted azaarenes to enones, and products were obtained in 60–96% yield. Lewis acid catalyzed benzylicC–H bond functionalization of alkyl-substituted azaarenes is described. The addition to N-tosyl imines proceeded under solvent-free conditions using various Lewis acids. Cu(OTf)2 was the best Lewis acid, and 1,2-addition proceeded at
A novel, hydrophilic and recyclable methoxypolyethylene glycol (PEG)-modulated s-triazine-based multifunctional Schiffbase/N,P-ligand L9 was prepared and used in Pd-catalyzed Heck-type carbonylative couplingreactions, affording diverse chalcone derivatives and 1,4-dicarbonyl esters in good yields.
A Straightforward Synthesis of Pyrazolines and Pyrazoles: Palladium-Catalyzed Carbonylative Vinylation-Cyclocondensation Reactions of Aryl Halides
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1002/ejoc.201100654
日期:2011.7.19
A novel consecutive one-pot synthesis of pyrazolines and pyrazoles starting from simple arylhalides, styrenes, carbon monoxide, and hydrazines has been established. Palladium-catalyzedcarbonylative vinylation of arylhalides gave the corresponding chalcones, which are trapped in situ by addition of hydrazines.
Squaramide-Catalyzed Enantioselective Michael Addition of Masked Acyl Cyanides to Substituted Enones
作者:Kin S. Yang、Antoinette E. Nibbs、Yunus E. Türkmen、Viresh H. Rawal
DOI:10.1021/ja409012q
日期:2013.10.30
Masked acyl cyanide (MAC) reagents are shown to be effective umpolung synthons for enantioselective Michaeladdition to substituted enones. The reactions are catalyzed by chiral squaramides and afford adducts in high yields (90–99%) and with excellent enantioselectivities (85–98%). The addition products are unmasked to produce dicyanohydrins that, upon treatment with a variety of nucleophiles, provide