An efficient and convenient highly enantioselective Michaeladdition of malononitrile to enones has been developed by using quinine as the organocatalyst. The adducts were isolated in excellent yield and high asymmetric induction (up to 95% ee). An easy route to difficultly accessible ester derivatives has been also disclosed.
One-Pot Quinine-Catalyzed Synthesis of α-Chiral γ-Keto Esters: Enantioenriched Precursors of <i>cis</i>
-α,γ-Substituted-γ-Butyrolactones
作者:Sara Meninno、Chiara Volpe、Alessandra Lattanzi
DOI:10.1002/adsc.201600427
日期:2016.9.1
enantioselective one‐pot synthesis of important building blocks, α‐chiral γ‐keto esters, has been developed by combining a quinine‐catalyzed Michael addition of malononitrile to trans‐enones followed by magnesium monoperoxyphthalate (MMPP) oxidation. These synthons proved to be useful reagents for a simple access to challenging cis‐α,γ‐disubstituted γ‐butyrolactones in good diastereoselectivity and
Stereoselective reductive radical cyclization of ketonitriles catalyzed by Cp2TiCl2 in the presence of chlorosilane and zinc
作者:Longhu Zhou、Toshikazu Hirao
DOI:10.1016/s0040-4020(01)00645-7
日期:2001.8
Reductive radical cyclization of ketonitriles was catalyzed by Cp2TiCl2 in the presence of Me3SiCl, zinc powder and imidazole, giving the 2-amino-3-cyano-2-cyclopenten-1-ols in moderate to good yields with high trans selectivity (up to 94% trans). The influence of the catalyst, chlorosilane, co-reductant, solvent, and temperature on both the yield and diastereoselectivity of the cyclized products was
In vitro antifungal evaluation and structure–activity relationships of a new series of chalcone derivatives and synthetic analogues, with inhibitory properties against polymers of the fungal cell wall
作者:Silvia N López、Marı́a V Castelli、Susana A Zacchino、José N Domı́nguez、Gricela Lobo、Jaime Charris-Charris、Juan C.G Cortés、Juan C Ribas、Cristina Devia、Ana M Rodrı́guez、Ricardo D Enriz
DOI:10.1016/s0968-0896(01)00116-x
日期:2001.8
Here we report the synthesis, in vitro antifungal evaluation and SAR study of 41 chalcones and analogues. In addition, all active structures were tested for their capacity of inhibiting Saccharomyces cerevisiae beta (1,3)-glucan synthase and chitin synthase, enzymes that catalyze the synthesis of the major polymers of the fungal cell wall. (C) 2001 Elsevier Science Ltd. All rights reserved.
An active and selective heterogeneous catalytic system for Michael addition
作者:Hoda Keipour、Mohammad A. Khalilzadeh、Abolfazl Hosseini、Afsaneh Pilevar、Daryoush Zareyee
DOI:10.1016/j.cclet.2012.02.006
日期:2012.5
Potassium fluoride doped natural zeolite was found to be an efficient and selective solid base catalyst for 1,4-Michael addition. The catalyst is easily prepared and the workup procedure simplified by simple filtration. All products were obtained in high yields as well as short reaction times. (C) 2012 Mohammad A. Khalilzadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.