Arabinogalactan propargyl ethers in the A3-coupling reaction with aldehydes and secondary cyclic amines

Abstract

A family of novel pharmacologically prospective carbohydrate polymer aminomethylpropargyl derivatives has been synthesized by CuI-catalyzed A³-coupling reaction of arabinogalactan propargyl ethers with aldehydes and secondary amines in DMSO at 23-65 °С. The arabinogalactan derivatives bearing phenyl, pyridinе, and furan moieties in combination with piperidyne, pyrrolidyne, morpholine fragments are prepared in up to 95 % yield and 0.3-2.0 degree of substitution. Conversion of the propargyl groups of the starting arabinogalactan ethers reaches in most cases 80-100 %. The non-catalyzed aminoalkylation (96-100 °С, degree of substitution up to 1.1) of propargylated AG proceeds both at the ethynyl and hydroxy centers to afford mainly the products of C-substitution. Some of the synthesized compounds and their hydrochlorination products show the pronounced bacteriostatic activity with respect to Gram-negative microorganism.

Keywords: A(3)-coupling reaction; Arabinogalactan functionalization; Carbaldehydes; Cu(I)-catalysis; Secondary amines.