Concurrent Oxidation of Alcohols and the Passerini Three‐Component Polymerization for the Synthesis of Functional Poly(ester amide)s

Abstract

A new polymerization method based on the Passerini three‐component reaction of a dicarboxylic acid, an alcohol, and a diisocyanide in the presence of an oxidant is reported. This polymerization involves the concurrent oxidation of alcohols by o‐iodoxybenzoic acid (IBX) and the Passerini three‐component polymerization. The kinetics of the alcohol oxidation and the Passerini reaction are investigated, and the results indicate that the cascade process can occur efficiently. The reaction conditions are optimized, and various functional alcohols are examined to get insight into the applicability of the method. Based on the optimized conditions, a variety of functional poly(ester amide)s are prepared in a one‐pot fashion via using 1,6‐diisocyanohexane, 1,6‐hexanedioic acid, different functional alcohols, and iodoxybenzoic acid. The introduction of functional pendant groups, especially alkynyl, alkenyl and epoxy groups, to the final poly(ester amide)s, provides an efficient way for further modification of the polymers.

Recent Advances in Cascade Reactions Initiated by Alcohol Oxidation

“…The combination of the bond (trans)formations described above and others can lead, in one pot, to various interesting products. Thus, a cascade Passerini three‐component one‐pot polymerization of a dicarboxylic acid, an alcohol, and a diisocyanide in the presence of an oxidant gives a poly(ester amide) with functional alkynyl, alkenyl, and epoxy pendant groups (Scheme ) . This polymerization involves the concurrent oxidation of various functional alcohols by o ‐iodoxybenzoic acid (IBX) and a three‐component polymerization; this allows bypass of commercially unavailable and unstable functional aldehydes (necessary for the traditional Passerini reaction), which significantly broadens the scope of the polymerization.…”

“…A tandem oxidation of alcohols and a Passerini three‐component polymerization has also been developed during this period by Li and co‐workers for the synthesis of functional poly(ester amide)s . This sparked from the recent and ongoing interest in the application of cascade strategies for the preparation of polymers with diverse functionalities and unique properties (see above, Section 2.4).…”

External-Oxidant-Based Multicomponent Reactions

“…Recently this approach has also been applied to the synthesis of functional poly(ester amides), by employing dicarboxylic acids and diisocyanides in combination with various alcohols and IBX as the oxidant. 9 Luca Banfi (left) graduated in chemistry in 1981 from the University of Milano (Professor Carlo Scolastico), and he accepted a position as Assistant Professor at the University of Genova in 1983, where he joined the group of Professor Giuseppe Guanti. He became associate professor in 1998 and full professor in 2000.…”

Two tandem multicomponent reactions for the synthesis of sequence-defined polymers

“…There are numerous synthetic strategies that can control the topological [12][13][14][15][16][17][18][19][20] and sequence structures of polymers [16,[21][22][23]. Among these strategies, multicomponent reactions have become powerful tools for the fabrication of macromolecules with controlled sequences because of their high efficiency, functional group tolerance, atom economy, and step economy [24][25][26][27][28]. Multicomponent reactions are performed in one pot and occur in a specific order.…”

“…The Passerini reaction is a multicomponent reaction involving a carboxylic acid, an isocyanide, and an aldehyde. This reaction has many advantages, such as mild reaction conditions, high efficiency, functional group tolerance, and atom economy [8,26]. Since Meier first introduced the use of the Passerini multicomponent reaction for the synthesis polymers, Passerini reactions have been extensively used in the synthesis of sequence-defined polymers.…”