Diamagnetic and paramagnetic amine derivatives of cellulose have been prepared from selectively oxidized cellulose precursors via the reductive amination method using sodium cyanoborohydride. 4-Amino-2,2,6,6-tetramethylpiperidine-1-oxyl was employed in the syntheses of nitroxide spin labelled cellulose derivatives 4 and 5 from 3-oxy-cellulose (1) and 6-O-triphenylmethyl-2-oxy-cellulose (2). Conversion of the linear polymer 1 into a highly branched, water soluble 3-deoxy-cellulose derivative 6 was accomplished by attachment of glucosamine side chains. 3-Amino-3-deoxy-cellulose 7 was obtained using ammonium acetate. A novel type of organometallic cellulose conjugate 8 was prepared by condensation of 2 and p-toluidine chromium tricarbonyl. Similarly, 1,10-diazo-18-crown-6 was added to 2 to form the crown ether derivative 9. The synthetic strategies involving either 6-O protected or unprotected oxy-cellulose intermediates are compared in terms of reaction yields and product properties.
Synthesis of selectively modified cellulose derivatives via reductive amination of 2-oxy- and 3-oxy-cellulose intermediates
