2-ELECTRON REDUCTION OF THE CATIONIC PROPAGATING END OF POLY(TETRAHYDROFURAN) INTO TERMINATING NUCLEOPHILES BY SAMARIUM IODIDE

Quantitative double electron reduction of the cationic propagation end of poly(tetrahydrofuran) into a terminating nucleophile was achieved by using samarium(II) iodide in the presence of hexamethylphosphoramid e. Termination of the resulting organosamarium group at the terminus o f the poly(THF) was attempted by using a variety of typical electrophi les such as aldehydes, ketones, isocyanates, and alkyl halides. The fu nctionality of the obtained poly(THF)s was 0.64-1.10 when aldehydes, k etones, or isocyanates were used as electrophiles, indicating that the reaction of the terminating nucleophile with electrophiles successive ly proceeded. In the case of using allyl bromide or benzyl bromide as a terminating agent, the functionality of the poly(THF)s decreased (0. 11-0.20).