화학공학소재연구정보센터
Polymer, Vol.113, 214-220, 2017
Direct arylation polycondensation of beta-unprotected chalcogen heteroles under phosphine-free conditions
We have demonstrated a direct arylation polycondensation of beta-unprotected chalcogen heteroles (furan, thiophene and selenophene) under phosphine-free conditions. The polycondensation of furan and thiophene using a solid-supported palladium catalyst, Pd/C, gave alternating copolymers (M-n = 8000 -10000), but the polycondensation of these monomers using common palladium catalysts such as Pd(OAc)(2) gave insoluble polymeric products resulting from beta-defects and network formation. Selenophene was a less reactive monomer for direct arylation using these catalysts, Pd/C and Pd(OAc)(2), yielding low molecular weight copolymer (M-n < 2500). On the other hand, PdCl2 was the most effective catalyst for the polycondensation of selenophene. The high molecular weight polymer (M-n = 11800) could be obtained. The H-1 NMR and UV-vis absorption spectra of the polymers obtained from furan, thiophene and selenophene were similar to those of the polymers synthesized by Suzuki-Miyaura cross-coupling polycondensation. (C) 2017 Elsevier Ltd. All rights reserved.