Stereoselective solid-phase synthesis of chiral piperidine derivatives by using an immobilized galactose auxiliary.

Stereoselektive kombinatorische Ugi-Mehrkomponenten-Synthese an fester Phase

Stereoselektive Festphasensynthese von chiralen Piperidinderivaten an einem immobilisierten Galactoseauxiliar

Stereoselective Combinatorial Ugi-Multicomponent Synthesis on Solid Phase

Sugars as Chiral Auxiliaries

Synthesis of a polymer-bound galactosylamine and its application as an immobilized chiral auxiliary in stereoselective syntheses of piperidine and amino acid derivatives.

A 2,3,4-tri-O-pivaloylated beta-D-galactopyranosyl azide bearing a hydroxy-functionalized spacer unit at the C-6 position of the galactose was synthesized and immobilized on the solid phase by using a polymer-bound chlorosilane. The azide was reduced to the corresponding galactopyranosylamine, which served as a versatile chiral auxiliary in highly diastereoselective Ugi four-component condensation reactions at ambient temperature. Fluoride-induced cleavage from the polymeric support furnished N-glycosylated N-acylated alpha-amino acid amides. The reaction of the immobilized galactosylamine with aldehydes gave rise to the corresponding aldimines, which underwent a domino Mannich-Michael cond…

Stereoselective Syntheses of Piperidine-Containing Heterocycles Using Carbohydrate Auxiliaries