Stereoselectivity of Superacid-Catalyzed Pictet−Spengler Cyclization Reactions
摘要:
High stereoselectivities were found in a wide range of superacid-catalyzed Pictet-Spengler cyclization reactions. Particularly in the cases of 2-alkyl-N-benzylidene-2-phenethylamines, an enhanced stereoselectivity was observed under the superacid conditions as compared with the corresponding weak acid (TFA)-catalyzed (monocationic) cyclization reaction of the N-benzylidene-2-(3',4'-dimethoxy)phenethylamines that bear electron-donating groups on the cyclizing aromatic ring. The computational study also supported the energetic favorability of the cyclization of the N,N-diprotonated imine and revealed a significantly early transition-state structure.
Disclosed is a compound having the formula:
pharmaceutically acceptable salts or solvates thereof and pharmaceutical compositions containing the same, wherein the structural variables are as defined herein. The compounds, salts and solvates of this invention are useful as LXR agonists.
Disclosed is a compound having the formula:
pharmaceutically acceptable salts or solvates thereof and pharmaceutical compositions containing the same, wherein the structural variables are as defined herein. The compounds, salts and solvates of this invention are useful as LXR agonists.