Multicomponent Tandem Reactions and Polymerizations of Alkynes, Carbonyl Chlorides, and Thiols

Multicomponent tandem reactions (MCTRs), with multiple bonds formed in a highly concise fashion in a single vessel, have been noted as one of the most powerful and popular synthetic strategies in modern organic chemistry. Attracted by their operational simplicity, synthetic efficiency, high atom economy, and environmental benefit, the MCTRs and the corresponding multicomponent tandem polymerizations (MCTPs) of alkynes, carbonyl chlorides, and aliphatic/aromatic thiols were developed. By combining the Sonogashira coupling reaction between alkynes and carbonyl chlorides, and the hydrothiolation reaction of electron-deficient alkynone intermediates, high atom economy was achieved in such one-pot, two-step, three-component reactions/polymerizations. The MCTPs can proceed efficiently under mild conditions near room temperature to afford sulfur-rich polymers with high molecular weight, high yield, high regioselectivity, and good stereoselectivity. Through the MCTPs of different combination of monofunctional and bifunctional monomers, polymers with tunable backbone structures and photophysical properties can be obtained. These polymers generally possess good solubility and film-forming ability. Their thin films enjoy high refractivity, and their photosensitivity enables easy modulation of the thin film refractive indices.