Remarkable Differences in Reactivity between Benzothiazoline and Hantzsch Ester as a Hydrogen Donor in Chiral Phosphoric Acid Catalyzed Asymmetric Reductive Amination of Ketones
as hydrogen donors in the chiral phosphoric acid catalyzed asymmetricreductiveamination of ketones with p‐anisidine. The asymmetricreductiveamination of ketones with a Hantzsch ester as a hydrogen donor provided the corresponding chiral amines exclusively, regardless of the structures of the ketones, whereas a similar transformation with a benzothiazoline provided chiral amines and p‐methoxyphenyl‐protected
<i>N</i>-1-Alkenyl-<i>N,S</i>-Diacyl-2-Aminobenzenethiols (Enamides) by Ring-Opening of 2,3-Dihydro-1,3-benzothiazoles with Aliphatic Carboxylic Anhydrides
The enamides 3 and 4 are obtained in good yields by treatment of 2,3-dihydro-1, 3-benzothiazoles 1 or N-acylderivatives 2 with aliphatic acid anhydrides.