93005-52-8Relevant academic research and scientific papers
Chiral Bronsted acid-promoted enantioselective desymmetrization in an intramolecular schmidt reaction of symmetric azido 1,3-hexanediones: Asymmetric synthesis of azaquaternary pyrroloazepine skeletons
Yang, Ming,Zhao, Yu-Ming,Zhang, Shu-Yu,Tu, Yong-Qiang,Zhang, Fu-Min
, p. 1344 - 1347 (2011)
The enantioselective desymmetrization of 2-substituted-2-azidopropyl 1,3-hexanediones through an asymmetric intramolecular Schmidt reaction using a chiral Bronsted acid has been developed for the first time. Synthetically interesting pyrroloazepine skeletons with an azaquaternary stereogenic center with up to 59 % ee are accessed effectively (see scheme; R=H, alkyl, or aryl). Copyright
Structure-dependent selective O- or C-trifluoroethylation of 1,3-dicarbonyls by mesityl(2,2,2-trifluoroethyl)iodonium triflate
Zhao, Cheng-Long,Yang, Jing,Han, Zhou-Zhou,Zhang, Cheng-Pan
supporting information, p. 23 - 30 (2017/10/30)
Reaction of [ArICH2CF3][OTf] with structurally diversified 1,3-dicarbonyls and an appropriate base at room temperature gave O-trifluoroethylated products, C-trifluoroethylated products, or a mixture of O- and C-trifluoroethylated products in good yields. The product type was dramatically dependent upon the structure of the starting 1,3-dicarbonyls in this reaction. The cyclic 1,3-diketones exclusively afforded the O-trifluoroethylated products, whereas the acyclic 1,3-diketones, β-keto esters, and malonates selectively or specifically formed the C-trifluoroethylated products. Li2CO3 facilitated the C-trifluoroethylation of acyclic 1,3-diketones and β-keto esters. The reaction proceeded under mild conditions, without pre-activation of 1,3-dicarbonyls and use of strong base, and demonstrated a catalyst-free structure-dependent regioselective trifluoroethylation of 1,3-dicarbonyls by mesityl(2,2,2-trifluoroethyl)iodonium triflate.
