A useful Michael addition reaction using nitroalkanes as the nucleophile and 4-oxo-enoates as the Michael acceptor has been disclosed, and the reaction allows expedient access to functionalized chiral gamma-keto esters in high yields and excellent enantioselectivities (up to 98% ee), with a low catalyst loading.
Stereoselective Assembly of Multifunctional Spirocyclohexene Pyrazolones That Induce Autophagy-Dependent Apoptosis in Colorectal Cancer Cells
作者:Xiang Li、Fei-Yu Chen、Jing-Wen Kang、Jin Zhou、Cheng Peng、Wei Huang、Mu-Ke Zhou、Gu He、Bo Han
DOI:10.1021/acs.joc.9b01098
日期:2019.7.19
Enantio- and diastereoselective synthesis of multifunctional spiropyrazolone scaffolds has been achieved using secondary amine-catalyzed [4 + 2] annulations of α,β,γ,δ-unsaturated pyrazolones with aldehydes. The pyrazolone substrates serve as C4 synthons to produce 6-membered, carbocycle-based, chiral spiropyrazolone derivatives. The synthesized chiral compounds showed potent toxicity against a panel