Strategies towards potent trypanocidal drugs: Application of Rh-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalide annulation and nitroalkene reactions for the synthesis of substituted quinones and their evaluation against Trypanosoma cruzi
作者:James M. Wood、Nishikant S. Satam、Renata G. Almeida、Vinicius S. Cristani、Dênis P. de Lima、Luiza Dantas-Pereira、Kelly Salomão、Rubem F.S. Menna-Barreto、Irishi N.N. Namboothiri、John F. Bower、Eufrânio N. da Silva Júnior
DOI:10.1016/j.bmc.2020.115565
日期:2020.8
Rhodium-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalideannulations and nitroalkene reactions have been employed for the synthesis of 56 quinone-based compounds. These were evaluated against Trypanosoma cruzi, the parasite that causes Chagas disease. The reactions described here are part of a program that aims to utilize modern, versatile and efficient synthetic methods for the one or two
Organocatalytic Enantioselective Michael–Acetalization–Reduction–Nef Reaction for a One-Pot Entry to the Functionalized Aflatoxin System. Total Synthesis of (−)- Dihydroaflatoxin D<sub>2</sub> and (−)- and (+)-Microminutinin
作者:Wei-Lun Huang、Arun Raja、Bor-Cherng Hong、Gene-Hsiang Lee
DOI:10.1021/acs.orglett.7b01473
日期:2017.7.7
enantioselective synthesis of the aflatoxin system with multiple stereocenters via a sequence of organocatalytic Michael–acetalization–reduction–Nef reactions that proceed with high enantioselectivities (90–99% ee). The one-pot reaction sequence provides a facile entry to the aflatoxin system, including dihydroaflatoxin D2, which includes a formal total synthesis of aflatoxin B2. The first total synthesis of (−)-
phosphine-catalyzed asymmetric dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita–Baylis–Hillman (MBH) carbonates or allenoate was developed. The reaction with MBH carbonates resulted in a series of cyclopentabenzofurans containing three contiguous stereocenters with good to high yields, diastereoselectivities and enantioselectivities. The use of allenoate also gave the target product
Chemoselective N-Heterocyclic Carbene-Catalyzed Cascade of Enals with Nitroalkenes
作者:Zijun Wu、Xu Wang、Fangyi Li、Jicheng Wu、Jian Wang
DOI:10.1021/acs.orglett.5b01692
日期:2015.7.17
An unprecedented N-heterocycliccarbenecatalyzed chemoselective and enantioselective cascade reaction of enals with nitroalkenes has been developed. A wide range of enantioenriched dihydrocoumarins has been prepared, and the reaction goes through an enolate intermediate generated under a catalytic process.
Relay catalysis: combined metal catalyzed oxidation and asymmetric iminium catalysis for the synthesis of Bi- and tricyclic chromenes
作者:Magnus Rueping、Jeremy Dufour、Modhu Sudan Maji
DOI:10.1039/c2cc00129b
日期:——
A catalytic asymmetric oxidative iminium-allenaminecascade allows the use of propargyl alcohols as stable substrates and yields valuable chiral bicyclic 4H-chromenes. A subsequent Michael addition-condensation domino reaction provides complex tricyclic 4H-chromenes in a highlyenantioselective fashion.