Spiro[indene-1,4′-oxa-zolidinones] Synthesis via Rh(III)-Catalyzed Coupling of 4-Phenyl-1,3-oxazol-2(3<i>H</i>)-ones with Alkynes: A Redox-Neutral Approach
作者:Zhongsu Liu、Wenjing Zhang、Shan Guo、Jin Zhu
DOI:10.1021/acs.joc.9b01804
日期:2019.9.20
C-H activation synthesis of heterocyclic spiro[4,4]nonanes has persistently witnessed the use of additional stoichiometric transition-metal oxidant when employing C═C bond as the spiro ring closure site. Herein, we have addressed the issue by reporting a redox-neutral strategy for spiro[indene-1,4'-oxa-zolidinones] synthesis via Rh(III)-catalyzed coupling of 4-phenyl-1,3-oxazol-2(3H)-ones with alkynes
An asymmetric transfer hydrogenation of 2-oxazolones in the presence of a chiral diamine ruthenium catalyst with potassium formate as a hydrogen source and potassium carbonate as an additive in 2,2,2-trifluoroethanol is described. A series of chiral 2-oxazolidinones were obtained with 29%–95% yields and 86%–>99% ee's. Furthermore, gram-scale synthesis of chiral 2-oxazolidinone and its downstream derivatizations