generated hydroxy‐o‐quinodimethanes with high stereoselectivity. We used a chiral organic catalyst, derived from natural cinchona alkaloids, to activate maleimides toward highly stereoselective Diels–Alder reactions. An unconventional mechanism of stereocontrol is operative, wherein the organocatalyst is actively involved in both the photochemical pathway, by leveraging the formation of the reactive photoenol
Hydrogen bond donor solvents enabled metal and halogen-free Friedel–Crafts acylations with virtually no waste stream
作者:Guangchang Liu、Bo Xu
DOI:10.1016/j.tetlet.2018.01.026
日期:2018.3
halogen-free Friedel–Crafts acylation protocol with virtually no waste stream generation. We propose a hydrogen bonding donor solvent will form a hydrogen bonding network and may provide significant rate enhancement for Friedel–Crafts reactions. Trifluoroacetic acid is one of the strongest H-bonddonor solvents, which is also volatile and can be easily recovered by distillation without need for reaction workup
A Cascade Approach to Naphthalene Derivatives from<i>o</i>-Alkynylbenzaldehydes and Enolizable Ketones via in-situ-Formed Acetals
作者:Seetharaman Manojveer、Rengarajan Balamurugan
DOI:10.1002/ejoc.201500497
日期:2015.7
o-alkynylbenzaldehydes and enolizable ketones. In situ acetal formation assists the condensation between o-alkynylbenzaldehydes and enolizable ketones to give chalcone derivatives under Bronsted acidic conditions. In situ acetal formation facilitates the reaction by increasing the electrophilicity of the carbonyl carbon of the o-alkynylaldehyde through oxonium ionformation, and also by enhancing the nucleophilicity
Light-induced phosphine-catalyzed asymmetric functionalization of benzylic C-H bonds
作者:Jiami Guo、Zi-An Shen、Xueting Zhou、Lei Dai、Yixin Lu
DOI:10.1007/s11426-022-1406-y
日期:2023.1
enantioselective functionalization of substrates bearing a benzylicC-H bond. In the presence of amino acid-derived bifunctional phosphine catalysts, a range of benzylic allylation products were obtained in good yields and with excellent enantioselectivities. The strategy disclosed herein offers new insight into the activation and functionalization of pronucleophiles containing less acidic C-Hbonds in the domain