Synthesis of Chamaecypanone C Analogues from in Situ-Generated Cyclopentadienones and Their Biological Evaluation
摘要:
A rhodium-catalyzed dehydrogenation protocol for the conversion of 3,5-diarylcyclopentenones to the corresponding 2,4-diarylcyclopentadienones has been developed. With this protocol, analogues of the cytotoxic agent chamaecypanone C have been synthesized via Diels-Alder cycloaddition between the cyclopentadienones and in situ-generated o-quinols. Biological evaluation of these analogues revealed a compound with higher activity as a microtubule inhibitor and cytotoxic agent in comparison with the parent structure.
Preparation of 4,6-Disubstituted α-Pyrones by Oxidative N-Heterocyclic Carbene Catalysis
作者:Armido Studer、Srikrishna Bera
DOI:10.1055/s-0036-1588336
日期:——
driving force in carbene catalysis, on the occasion of his 70th birthday Abstract An efficient synthesis of 4,6-disubstituted α-pyrones employing redox activation of enals using N-heterocyclic carbene catalysis is reported. The strategy uses aroyl-substituted nitromethanes and enals as substrates and reactions proceed through an addition–elimination–lactonization sequence. On one hand the nitro group
The reactions of 2-pyrones and coumarins with hydrochlorosilane, elemental selenium, and 4-dimethylaminopyridine (DMAP) gave 2-selenopyrones and selenocoumarins in moderate to good yields. Their fo...
N-Heterocyclic Carbene-Catalyzed Annulation of Ylides with Ynals: Direct Access to α-Pyrones
作者:Ming Lang、Qianfa Jia、Jian Wang
DOI:10.1002/asia.201800595
日期:2018.9.4
We herein report an N‐HeterocyclicCarbene (NHC)‐catalyzed annulation of ylides with ynals that provides an efficient protocol to make 4,6‐disubstituted α‐pyrones. This method affords a variety of α‐pyrones in good to high yields as well as broad substrate scope and good functional group tolerance.
N-Heterocyclic carbene-catalyzed cascade epoxide-opening and lactonization reaction for the synthesis of dihydropyrone derivatives
作者:Jing Qi、Xingang Xie、Jinmei He、Ling Zhang、Donghui Ma、Xuegong She
DOI:10.1039/c1ob05854a
日期:——
N-Heterocyclic carbene was employed as an efficient organic catalyst to catalyze a cascadeepoxide-opening and lactonization reaction. This organocatalytic process could transform various readily accessible γ-epoxy-α,β-enals into dihydropyrone derivatives in good to excellent yields.