Highly Stereoselective Ene Reaction of Aldimines with 2-(Alkylthio)allyl Silyl Ethers
摘要:
A stereoselective ene reaction of aldimines with 2-(alkylthio)allyl silyl ethers was developed. Under the influence of Lewis acids, N-acylimine or geminal biscarbamates reacted with a (Z)-2-(methylthio)allyl silyl ether to afford syn adducts in >94% selectivity.
An efficient preparation of β-amino-α,α-difluoroketones 4 was developed. Reactions of 1,1-difluorovinylmethylethers 1 with N-acyliminiumintermediates, generated by treating biscarbamates 2 with trifluoromethanesulfonic anhydride (Tf2O) in the presence of molecular sieves 4A (MS 4A), provided 4 in good yields.