A chiral N-heterocyclic carbene (NHC)-catalyzed [4 + 2] annulation of γ-chloroenals and α-arylidene pyrazolinones was developed in the absence of expensive oxidants. The reaction proceeds smoothly via a vinyl enolate intermediate to afford spirocyclohexane pyrazolones in moderate to good yield (up to 86%) with high diastereoselectivities (up to 15:1 dr) and excellent enantioselectivities (up to >99%
adopted activity-directed combinatorial chemical synthesisstrategy to optimize this hit compound. Compound b36 was found to be the noncompetitive and the most promising one with IC50 values of 5.96 ± 0.61 μM against PHGDH. Compound b36 inhibited the proliferation of human breast cancer and ovarian cancer cells, reduced intracellular serine synthesis, damaged DNA synthesis, and induced cell cycle arrest
Optically Active 4-Substituted 5-Nitropentan-2-ones: Valuable Chiral Building Blocks for the Stereocontrolled Construction of Spiro-Pyrazolone Scaffolds with Five Contiguous Stereogenic Centers
作者:Jiao Sun、Cuiping Jiang、Zhenghong Zhou
DOI:10.1002/ejoc.201501449
日期:2016.2
The application of readily available opticallyactive4-substituted5-nitropentan-2-ones as chiralbuildingblocks in the stereocontrolledconstruction of spiro-pyrazolonescaffolds was investigated. In the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (1 equiv.) opticallyactive4-substituted 5-nitropentan-4-ones exhibited excellent chiral inducing abilities in the diastereoselective cascade Michael/aldol
A new and efficient one-pot strategy combining catalyst-free synthesis and iodinecatalysis has been developed for the synthesis of dihydrofuropyrimidines and spirodihydrofuropyrimidine pyrazolones. This approach affords products in moderate to high yields (up to 96%) with excellent diastereoselectivities (up to >25 : 1 dr). The reaction is simple to carry out and is metal-free.
DMAP Catalyzed Domino Rauhut–Currier Cyclization Reaction between Alkylidene Pyrazolones and Nitro-olefins: Access to Tetrahydropyrano[2,3-<i>c</i>]pyrazoles
作者:Nimisha Bania、Buddhadeb Mondal、Sounak Ghosh、Subhas Chandra Pan
DOI:10.1021/acs.joc.0c02871
日期:2021.3.5
Herein, we employ unsaturated pyrazolones in the Rauhut–Currier reaction for the first time. A domino Rauhut–Currier cyclization reaction has been developed between unsaturated pyrazolones and nitro-olefins. The trisubstituted tetrahydropyrano[2,3-c]pyrazoles were obtained in moderate to high yields with excellent diastereoselectivities. A few applications including a synthesis of disubstituted tetrahydropyrano[2
在本文中,我们首次在Rauhut-Currier反应中使用了不饱和吡唑啉酮。在不饱和吡唑啉酮和硝基烯烃之间发展了多米诺Rauhut-Currier环化反应。三取代四氢吡喃并[2,3- c ]吡唑以中等至高收率获得,具有非对映选择性。已经证明了包括合成二取代的四氢吡喃并[2,3- c ]吡唑在内的一些应用。还使用手性DMAP催化剂研究了该方法的初步催化不对称形式。