Sequence Regulated Poly(ester-amide)s Based on Passerini Reaction

Abstract

Multicomponent polymerization based on Passerini reaction is described. Room temperature polymerization of dicarboxyl acid, monoaldehyde, and diisocyanide leads to the formation of a new type of sequence regulated poly(ester-amide)s in an efficient one-pot process. The polymerization was confirmed to be a stepwise mechanism, and the resulting polymers were characterized and determined to be linear polymers with a sequence regulated backbone repeating unit of ester−ester−amide− amide. When functional aldehydes were used, functional side groups could be easily introduced at the same time, providing a simple way for further modification.

Recent developments in the synthesis of sequence controlled polymers

“…In this method, the sequence can be built either by the intrinsic components of the reaction or by template monomers with built-in sequences. Li and coworkers [14] prepared sequence regulated poly(ester-amide) through Passerini reaction among dicarboxylic acid, aldehyde, and diisocyanide. The order of monomer connectivity in the reaction was transmitted into the sequence of the polymer products ( Figure 8).…”

“…In a general sense, "sequence controlled polymer" was referred to as any polymer product that exhibits ordered monomer repeat units, segments, or location of functionalities on the chain [13]. In some cases, the term "sequence regulated polymer" was used in a similar way [14][15][16][17]. The nomenclature of "sequence defined" [18][19][20] or "sequence specific" [21,22] polymer emphasized particular order of monomer units which were connected periodically or aperiodically.…”

Application of named reactions in polymer synthesis

“…Synthetic strategy for Passerini polymerization via the AA/BB/C approach [86][87][88]. molecular weight polyesters (Scheme 21(a)) [86].…”

“…Therefore, Passerini multi-component polymerization (MCP) was found to be a very powerful synthetic strategy to produce functionalized polymers from two bifunctional building blocks. Li et al [87] then followed this strategy using diisocyanides instead of dialdehydes to prepare sequence-regulated poly(ester- amide)s (Scheme 21(b)); they found that the molecular weight was directly dependent on the amount of monogroup component. The easily controlled polymer molecular weight together with the functional group tolerance offers many possibilities for the construction of a variety of new polymer architectures using this synthetic strategy.…”

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].…”