Developing gold- and silver-catalyzed dehydrogenative cross-coupling toward donor-acceptor polymer synthesis

Abstract

pi-Conjugated polymers are materials of interest for use in organic electronics. Within these polymers, donor-acceptor polymers are favorable for solar cell applications due to improved charge mobility, better absorption in the low energy region of the solar spectrum, and tunable band gaps. One of the barriers to commercializing these donor-acceptor materials is that their synthetic pathways are complex because of the alternating repeat units in the polymer. To address this, the applications of cross dehydrogenative coupling (also called oxidative CH/CH cross-coupling) toward the synthesis of donor-acceptor polymers was explored. In this work, the roles of specific reagents in a one-pot gold- and silver-catalyzed cross dehydrogenative coupling and the factors that contribute to selectivity for cross-coupling rather than homo-coupling are elucidated. Based on our results, we conclude that the difference in rate of C-H activation by gold and silver dominate the percentage of alternating repeat units in the final polymer, which may be exploited to control the ratio of electron-rich to electron-poor monomers.