A general and green procedure for the synthesis of organochalcogenides by CuFe<sub>2</sub>O<sub>4</sub>nanoparticle catalysed coupling of organoboronic acids and dichalcogenides in PEG-400
作者:Debasish Kundu、Nirmalya Mukherjee、Brindaban C. Ranu
DOI:10.1039/c2ra22415a
日期:——
A general and efficient procedure has been developed for the synthesis of organochalcogenides (selenides and tellurides) by a simple reaction of organoboronic acids and dichalcogenides catalysed by CuFe2O4 nanoparticles in PEG-400 without any ligand. This protocol offers the scope for access to a wide spectrum of chalcogenides including diaryl, aryl–heteroaryl, aryl–styrenyl, aryl–alkenyl, aryl–allyl, aryl–alkyl and aryl–alkynyl versions. The catalyst is magnetically separable and recyclable eight times without any loss of appreciable catalytic activity. The products are obtained in high purities after evaporation of solvent followed by filtration column chromatography.
Catalytic Enantioselective Inverse-Electron-Demand Diels–Alder Reaction of 2-Pyrones and Vinyl Selenides
作者:Quan Cai、Xin-Yu You
DOI:10.1055/a-1990-5276
日期:——
We report an asymmetric inverse-electron-demand Diels–Alder reaction of electron-deficient 2-pyrones with various phenyl vinyl selenides catalyzed by a chiralbis(oxazoline)/Cu(OTf)2 complex. By using a side-arm-modified chiralbis(oxazoline)ligand, a variety of [2,2,2]-bicyclic lactones with phenyl selenide substituents were obtained in good to excellent yields (up to 99%) and enantioselectivities