Modular In Situ Functionalization Strategy: Multicomponent Polymerization by Palladium/Norbornene Cooperative Catalysis

Abstract

Herein, we report a cooperatively palladium/norbornene-catalyzed polymerization, which simplifies the synthesis of functional aromatic polymers, including conjugated polymers. Specifically, an A B C-type multicomponent polymerization that is based on an ortho amination/ipso alkynylation reaction was developed for the preparation of various amine-functionalized arylacetylene-containing polymers. Within a single catalytic cycle, the amine side chains are site-selectively installed in situ by C-H activation during the polymerization process, which represents a major difference from conventional cross-coupling polymerizations. This "in situ functionalization" strategy enables the modular incorporation of functional side chains starting from simple monomers, thereby conveniently affording a diverse range of functional polymers.

Catellani Reaction: An Enabling Technology for Vicinal Functionalization of Aryl Halides by Palladium(0)/Norbornene Cooperative Catalysis

“…Overall, these unique protocols have considerably expanded to diverse fields such as the total synthesis of natural products [79,84,102,[120][121] and the development of new materials. [122][123] Moreover, it should be mentioned that the Pd(II)/NBE-catalyzed reactions have also gained very remarkable achievements by Bach, Dong, Yu, Zhou and others. This type of chemistry, which was not included in this short review, has already been well discussed in several recent reviews.…”

“…Overall, these unique protocols have considerably expanded to diverse fields such as the total synthesis of natural products [ 79,84,102,120‐121 ] and the development of new materials. [ 122‐123 ]…”

Multicomponent Polymerization for π‐Conjugated Polymers

“…The branched module approach forms polymer backbones and side chains simultaneously, also known as an in situ functionalization strategy. [ 21 ] It maximizes the modularity of multicomponent reactions through the simultaneous introduction of two distinct types of modules—main‐chain and side‐chain modules. Owing to modular one‐step operations, this approach is expected to be facile for preparing polymer libraries with diverse side‐chains.…”

Selectivity in multiple multicomponent reactions: types and synthetic applications

“…In these processes, the reactivity of the equivalent FGs is nearly identical in the reactants and in the oligo/polymeric intermediates, as they are usually connected through long linear alkyl chains. Representative examples include polymerizations using Biginelli [12], Passerini [13], Ugi [14], metal-catalyzed MCRs [15], and reactive combinations involving an alkyne-sulfonyl azide nucleophile [16] and sulfur, amines and isocyanides [17] (Scheme 3).…”