A green H2O-promoted solvent-free hydroamination of electron-deficient terminal alkynes with amines has been developed. All secondary amines, including aliphatic and aromaticamines, gave the corresponding (E)-enamines in good to excellent yields, whereas primary aromaticamines afforded Z-configured products in moderate yields. Propiolates, propyn-1-ones, propynamides, and 1-(ethynylsulfonyl)-4-methylbenzene
An efficientsynthesis of various β-enaminoesters has been achieved via Reformatskyreaction with disubstituted formamides as novel electrophiles. The exclusive β-enaminoester E-isomers were obtained in 60–72% yield.
Synthesis of 2-aminofurans and 2-unsubstituted furans via carbenoid-mediated [3 + 2] cycloaddition
作者:Yaojia Jiang、Vanessa Zhong Yue Khong、Emmanuvel Lourdusamy、Cheol-Min Park
DOI:10.1039/c2cc18139h
日期:——
An efficient dual synthetic manifold for 2-aminofurans and 2-unsubstituted furans has been developed. The carbenoid-mediated [3 + 2] cycloaddition of copper carbenoids with enamines provides 2-amino-2,3-dihydrofurans which serve as common intermediates for both 2-aminofurans and 2-unsubstituted furans.
An efficientpalladium-catalyzed oxidative amination of olefins with secondary anilines for the synthesis of tertiary (E)-enamines has been developed. Trimethylacetic acid (PivOH) played an important role in the reaction. This protocol tolerates a range of functional groups and is a reliable method for direct synthesis of tertiary (E)-enamines in high yields undermildconditions.