Activated Internal Alkyne‐Based Polymerization^†

Abstract

As an emerging and efficient polymerization methodology, activated internal alkyne-based polymerization has been considered as a powerful tool for the construction of polymers with diverse architectures and versatile functions. This review focuses on the recent progresses in the polymerization using mono-activated, di-activated, in-situ generated, ring-strained ethynyl groups as substrates, coupling with post-modification on premade polymers containing activated internal ethynyl moieties. Representative examples are used to illustrate the fundamental design strategy, the development of polymerization and post-functionalization, along with the properties and potential applications of the prepared polymers. Moreover, the challenges and perspectives in terms of new-type active alkynes, green polymerization methodology, tailored regio-/stereoselectivity modulation, and potentially expanded application in this area are also discussed.

Organic Base-Facilitated Thiol–Thioalkyne Reaction with Exclusive Regio- and Stereoselectivity

“…With the above positive results in hand, we next conducted the polymerizations of dithioalkynes A with dithiols B (Table ). It is worth mentioning here that internal alkynes are still scarcely used in the synthesis of polymers through the thiol–yne click polymerization. ,, In the limited cases, regio- and stereoselectivity could not be controlled in the treatment of unactivated internal alkynes. ,− Though the regioselectivity was well regulated in the polymerization of activated internal alkynes bearing electron-deficient groups, absolute stereoselectivity still could not be achieved. ,, Under the unoptimized condition, reactions listed in Table were found to proceed rapidly. At ambient temperature, both of the diyne and dithiol monomers were consumed completely in half an hour.…”

“…Investigation on its use in the synthesis of sulfur-rich polymers was further conducted, whose result indicates it as a promising tool for polymerizations of internal alkynes. 39,40 ■ RESULTS AND DISCUSSION…”

“…It is worth mentioning here that internal alkynes are still scarcely used in the synthesis of polymers through the thiol− yne click polymerization. 39,40,46 In the limited cases, regio-and stereoselectivity could not be controlled in the treatment of unactivated internal alkynes. 12,47−51 Though the regioselectivity was well regulated in the polymerization of activated internal alkynes bearing electron-deficient groups, absolute stereoselectivity still could not be achieved.…”

“…Notably, this protocol exhibits excellent tolerance for diverse environmentally benign solvent systems, including the mixture of water with dimethyl sulfoxide (DMSO) which is extensively employed in biology-related research. Investigation on its use in the synthesis of sulfur-rich polymers was further conducted, whose result indicates it as a promising tool for polymerizations of internal alkynes. , …”

Photocatalytic Metal‐Free Radical Hydrosilylation for Polymer Functionalization†

“…Simply synthesizing functional polymers has attracted increasing attention, [ 1‐7 ] and one of the most effective ways is to functionalize unsaturated polymers by hydrosilylation. [ 2 ] Silane‐ functionalized polymers have potential applications in adhesives, rubbers, drug delivery agents, etc .…”