<i>N</i>-Trifluoromethylthiophthalimide: A Stable Electrophilic SCF<sub>3</sub>-Reagent and its Application in the Catalytic Asymmetric Trifluoromethylsulfenylation
Cinchona alkaloid catalysts in combination with air‐ and moisture‐stable N‐trifluoromethylthiophthalimide as electrophilic SCF3 source enabled the catalytic enantioselective trifluoromethylsulfenylation. Thus, a series of α‐SCF3 esters that bear a quaternary carbon stereogenic center were obtained with excellent yield and enantioselectivity. Moreover, the products can be readily converted into valuable
Enantioselective Iron-Catalyzed Azidation of β-Keto Esters and Oxindoles
作者:Qing-Hai Deng、Tim Bleith、Hubert Wadepohl、Lutz H. Gade
DOI:10.1021/ja402082p
日期:2013.4.10
The first example of Fe-catalyzed enantioselective azidations of β-ketoesters and oxindoles using a readily available N3-transfer reagent is reported. A number of α-azido-β-keto esters were obtained with up to 93% ee, and this methodology also generates 3-substitued 3-azidooxindoles with high enantioselectivities (up to 94%).
报道了使用现成的 N3 转移试剂对 β-酮酯和羟吲哚进行 Fe 催化的对映选择性叠氮化的第一个例子。获得了许多具有高达 93% ee 的 α-叠氮基-β-酮酯,并且该方法还产生了具有高对映选择性(高达 94%)的 3-取代的 3-叠氮基吲哚。
Organic base-promoted enantioselective electrophilic cyanation of β-keto esters by using chiral phase-transfer catalysts
作者:Min Chen、Zhi-Tang Huang、Qi-Yu Zheng
DOI:10.1039/c5ob01301a
日期:——
Highly enantioselective electrophilic cyanation of β-keto esters with hypervalent iodine(iii) as the cyanating reagent induced by cinchona alkaloid-based chiral phase-transfer catalysts using an organic base is reported.
Copper-Boxmi Complexes as Highly Enantioselective Catalysts for Electrophilic Trifluoromethylthiolations
作者:Qing-Hai Deng、Christoph Rettenmeier、Hubert Wadepohl、Lutz H. Gade
DOI:10.1002/chem.201303641
日期:2014.1.3
The enantioselectivetrifluoromethylthiolation of β‐ketoesters using chiral copper–boxmicomplexes as catalysts is reported. A number of α‐SCF3‐substituted β‐ketoesters have been obtained with up to >99 % enantiomeric excess (ee), and the trifluoromethylthiolated products were then transformed diastereoselectively to α‐SCF3‐β‐hydroxyesters with two adjacent quaternary stereocenters.
Asymmetric construction of quaternary stereocenters by magnesium catalysed direct amination of β-ketoesters using in situ generated nitrosocarbonyl compounds as nitrogen sources
作者:Biplab Maji、Mahiuddin Baidya、Hisashi Yamamoto
DOI:10.1039/c4sc01272k
日期:——
An oxophilic magnesium salt in combination with a chiral N,N′-dioxide ligand switches the chemoselectivity of an ambident nitrosocarbonyl species to nitrogen for the highly enantioselective α-amination of β-ketoesters.