Cu(I)-Catalyzed Heterogeneous Multicomponent Polymerizations of Alkynes, Sulfonyl Azides, and NH₄Cl

Abstract

Nitrogen-containing polymers are a group of fascinating materials, which are usually prepared from nitrogen-containing organic monomers produced from NH3 gas or aqueous solution of ammonia. The direct utilization of safe, clean, convenient, and inexpensive inorganic NH4Cl salt as a nitrogen source for the construction of functional polymers is highly desired but challenging. Multicomponent polymerizations, with their strong designability, structural diversity, high efficiency, simple procedure, and environmental benefit, have been proven to be powerful tools to efficiently convert simple monomers to complex polymer materials. In this work, Cu­(I)-catalyzed multicomponent polymerizations of alkynes, sulfonyl azides, and NH4Cl are developed, utilizing simple inorganic NH4Cl salt to serve as a monomer for the preparation of functional poly­(sulfonyl amidine)­s. The heterogeneous polymerization goes smoothly at room temperature in CH2Cl2/tetrahydrofuran, which is also applicable to a range of different monomer structures, affording seven poly­(sulfonyl amidine)­s with high yields (up to 96%) and high molecular weights (up to 47,100 g/mol). Unique functionalities such as photophysical properties and metal ion detection can be introduced to the poly­(sulfonyl amidine)­s either from monomer structures or the in situ generated product structures, rendering them as selective and sensitive fluorescence sensors for Ru3+. This multicomponent polymerization showed high synthetic efficiency with environmental and economic benefit, which has opened up a feasible synthetic method of using inorganic NH4Cl salt instead of organic amines, isocyanates, isocyanides, or nitriles to construct nitrogen-containing polymers, demonstrating a promising synthetic approach for the synthesis of advanced functional polymer materials.

Copper-catalyzed Z-selective synthesis of acrylamides and polyacrylamides via alkylidene ketenimines

“…Multicomponent polymerization (MCP) is a highly efficient polymerization strategy derived from corresponding MCR, rapidly affording functional polymers with diverse structures 7 – 21 . Based on the results using di -OBoc-alkyne, benzyl azides, and water, we further forwarded such transformation into MCP to prepare copolymers containing both acrylamide and triazole segments using di -OBoc-alkyne, di -azide, and water (Fig.…”

“…Chang and Fokin et al first discovered ketenimines could be quickly formed in situ by copper-catalyzed electron-withdrawing azide-alkyne cycloadditions 5 , 6 . We and others have also been engaged to convert ketenimines using various nucleophiles and electrophiles which rapidly promoted the burgeoning growth of multicomponent reactions (MCR) in organic chemistry 7 – 13 and multicomponent polymerizations (MCP) in polymer science 14 – 21 involving ketenimine intermediates (Fig. 1a ).…”

De Novo Design of Entropy-Driven Polymers Resistant to Bacterial Attachment via Multicomponent Reactions

“…In the present study, entropy-driven polymers resistant to bacterial attachment are fabricated by introducing citric alcohol into polymer side chains via three MCRs. MCRs including Passerini, Ugi, Biginelli, Hantzsch, and Debus–Radziszewski reactions as well as alkyne-based and metal-catalyzed MCRs are widely used in polymer chemistry to develop elegant polymers. − Considering the broad scope of MCRs, the application of different MCRs in the present system could lead to a wide variety of new entropy-driven “antibacterial” polymers bearing different “razors” in the side chains.…”

Recent Advances in Diversity‐Oriented Polymerization Using Cu‐Catalyzed Multicomponent Reactions

“…Subsequently, Hu and co‐workers conducted Cu‐3CP directly using an inexpensive inorganic salt, NH 4 Cl (Figure 4b). [ 42 ] Heterogeneous polymerization occurred because of the insolubility of NH 4 Cl in CH 2 Cl 2 /tetrahydrofuran. Although the solubility of NH 4 Cl was poor, the polymerization proceeded efficiently, affording seven different polymers in high yields of up to 96%, with an M w up to 47.1 kDa (Figure 4b).…”