Enantioselective Photochemical Rearrangements of Spirooxindole Epoxides Catalyzed by a Chiral Bifunctional Xanthone
作者:Mark M. Maturi、Alexander Pöthig、Thorsten Bach
DOI:10.1071/ch15280
日期:——
The title compounds were shown to undergo an enantioselective photochemical rearrangement to 3-acylindolin-2-ones (16–33 % ee). A xanthone, which is tethered via an anellated oxazole to a chiral 1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-one scaffold, efficiently catalyzed this reaction at λ 366 nm, presumably by triplet sensitization. The observed enantioselectivity can be explained by hydrogen bonding
A Facile Method for the Synthesis of 3-Alkyloxindole
作者:Tai-Ping Du、Gang-Guo Zhu、Jian Zhou
DOI:10.2174/157017812800167420
日期:2012.3.1
Benzylamine in combination with acetic acid was identified as a powerful catalyst for the condensation of oxindole with aldehydes, acetone or cyclic ketones. A variety of 3-alkyloxindoles could be readily prepared in 10 mmol scale via the sequential benzylamine acetate catalyzed condensation of oxindoles with aldehydes (or ketones) and conjugate reduction by NaBH4.
Asymmetric Synthesis of Spirooxindole δ-Lactones with Vicinal Tertiary and Quaternary Stereocenters via Regio-, Diastereo-, and Enantioselective Organocatalytic Vinylogous Aldol-cyclization Cascade Reaction
作者:Jeng-Liang Han、You-Da Tsai、Chia-Hao Chang
DOI:10.1002/adsc.201701104
日期:2017.11.23
A highly region-, diastereo-, and enantioselectiveorganocatalytic vinylogous aldol-cyclization cascade reaction of prochiral 3-akylidene oxindoles to isatins has been achieved by using bifuctional organocatalysts. A variety of enantioenriched spirooxindole δ-lactones with vicinal tertiary and quaternary stereocenters were generated in good to excellent yields with good to high diastereoselectivities
Herein, we present a general electrochemical method to access unsymmetrical 3,3-disubstituted oxindoles by direct C–H functionalization where the oxindole fragment behaves as an electrophile. This Umpolung approach does not rely on stoichiometric oxidants and proceeds under mild, environmentally benign conditions. Importantly, it enables the functionalization of these scaffolds through C–O, and by
Visible light induced hydrodifluoromethylation of alkenes derived from oxindoles with (difluoromethyl)triphenylphosphonium bromide
作者:Wei-Qiang Hu、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1016/j.jfluchem.2018.01.013
日期:2018.4
A visible light induced hydrodifluoromethylation of alkenes derived from oxindoles with (difluoromethyl)triphenylphosphonium bromide was developed. This reaction delivers a series of previously unknown difluoromethylated oxindoles containing CCF2H quaternary centers in moderate to excellent yields. The resulting CF2H-containing oxindoles are potentially useful in drug discovery.