Asymmetric Synthesis of Axially Chiral 1-Aryl-5,6,7,8-tetrahydroquinolines by Cobalt-Catalyzed [2 + 2 + 2] Cycloaddition Reaction of 1-Aryl-1,7-octadiynes and Nitriles
The asymmetricsynthesis of a range of axially chiral 2-arylpyridines by a cobalt-catalyzed [2 + 2 + 2] cycloaddition reaction is described. The use of a planar chiral (1-neomenthylindenyl)cobalt(COD) complex under photochemical conditions is the key for reacting the 1-naphthyldiynes with a range of differently functionalized nitriles, giving the enantiomericatropoisomers with high chemical yields
Investigations on the synthesis of monoarylated diynes by monoprotection/cross-coupling/deprotection approach
作者:Karolin Kral、Marko Hapke
DOI:10.1016/j.tetlet.2012.03.118
日期:2012.6
The presented experimental work investigates the usefulness of temporary monoprotection of symmetrical terminal diynes in the coupling with aryl iodides. The monoprotection/cross-coupling/deprotection approach proved to be efficient for the coupling of diynes with aryl substrates avoiding the formation of diarylated byproducts. The high importance of the ratio of solvents in the Sonogashira coupling