This feature article provides a compilation of tools available for preparing well-defined peptide/protein-polymer conjugates, which are defined as hybrid constructs combining (i) a defined number of peptide/protein segments with uniform chain lengths and defined monomer sequences (primary structure) with (ii) a defined number of synthetic polymer chains. The first section describes methods for post-translational, or direct, introduction of chemoselective handles onto natural or synthetic peptides/proteins. Addressed topics include the residue- and/or site-specific modification of peptides/proteins at Arg, Asp, Cys, Gln, Glu, Gly, His, Lys, Met, Phe, Ser, Thr, Trp, Tyr and Val residues and methods for producing peptides/proteins containing non-canonical amino acids by peptide synthesis and protein engineering. In the second section, methods for introducing chemoselective groups onto the side-chain or chain-end of synthetic polymers produced by radical, anionic, cationic, metathesis and ring-opening polymerization are described. The final section discusses convergent and divergent strategies for covalently assembling polymers and peptides/proteins. An overview of the use of chemoselective reactions such as Heck, Sonogashira and Suzuki coupling, Diels-Alder cycloaddition, Click chemistry, Staudinger ligation, Michael's addition, reductive alkylation and oxime/hydrazone chemistry for the convergent synthesis of peptide/protein-polymer conjugates is given. Divergent approaches for preparing peptide/protein-polymer conjugates which are discussed include peptide synthesis from synthetic polymer supports, polymerization from peptide/protein macroinitiators or chain transfer agents and the polymerization of peptide side-chain monomers. 相似文献
This paper describes the successful application of the Suzuki polycondensation (SPC) to the synthesis of high molecular weight polyphenylenes using aryl dichloride monomers. From readily available starting material, two meta‐dichloromonomers ( 2b and 2c ) were prepared and subjected to SPC with benzene 1,4‐diboronic acid ester to produce reasonably high molar mass poly(para‐meta‐phenylene)s 4a and 4b , respectively, if freshly prepared Pd‐catalyst, Buchwald ligand and the base K3PO4 were used. The polymer with butoxy substituent ( 4a ) was compared regarding GPC molar mass and glass transition temperature with its exact same congener which had been synthesized in a previous work starting from a meta‐dibromo monomer. This comparison unequivocally confirms the molar masses achieved and, thus, establishes the first reported case of a SPC using aryl chloride monomers, instead of the more expensive and less amply available aryl bromides which had to be used otherwise.
The advent of well-defined catalysts for olefin metathesis which combine high activity, durability, and excellent tolerance towards polar functional groups has revolutionized the field. The past decade has seen the rapid embrace of these reagents as tools for advanced organic and polymer chemistry and the success of this development is witnessed by a plethora of elegant applications to the synthesis of natural and nonnatural products. This review article provides an overview of these developments and intends to familiarize the reader with some very recent advances which hold the promise to expand the scope of the reaction even further. Moreover, the positive impact of metathesis on the fundamental logic of retrosynthetic planning is demonstrated by means of typical examples. Finally, it will be shown that metathesis is by no means restricted to alkenes as substrates, and some comments on metathesis reactions following unconventional mechanistic pathways will also be presented. 相似文献
Coordination-insertion polymerization systems have long been superior to their anionic, cationic, and radical polymerization counterparts with regard to stereochemical control. However, until five years ago, these metal-based insertion methods were inferior to ionic and radical mechanisms in the category of living polymerization, which is simply a polymerization that occurs with rapid initiation and negligible chain termination or transfer. In the last half decade, the living insertion polymerization of unactivated olefins has emerged as a powerful tool for the synthesis of new polymer architectures. Materials available today by this route range from simple homopolymers such as linear and branched polyethylene, to atactic or tactic poly(alpha-olefins), to end-functionalized polymers and block copolymers. This review article summarizes recent developments in this rapidly growing research area at the interface of synthetic and mechanistic organometallic chemistry, polymer chemistry, and materials science. While special emphasis is placed on polymer properties and novel polymeric architectures, most of which were inaccessible just a decade ago, important achievements with respect to ligand and catalyst design are also highlighted. 相似文献
The development of transition-metal-catalyzed dehydrocoupling reactions as a synthetic method for the formation of main-group element-element bonds provides an increasingly attractive and convenient alternative to traditional routes such as salt metathesis/elimination-type reactions. Since the first reported examples in the early 1980s, there has been a rapid expansion of this field, with extensions to a wide variety of metal-mediated homonuclear and heteronuclear bond-forming processes. Applications of this new chemistry in molecular and polymer synthesis, materials science, hydrogen storage and the transfer hydrogenation of organic substrates are attracting growing attention. An overview of this emerging area is presented in this Concepts article with a focus on recent results. 相似文献
The latest developments and in particular important synthetic aspects for the preparation of modern HPLC supports are reviewed. In this context, the chemistry of inorganic supports based on silica, zirconia, titania or aluminum oxide as well as of organic supports based on poly(styrene-divinylbenzene), acrylates, methacrylates and other, more specialized polymers is covered. Special consideration is given to modern approaches such as sol-gel technology, molecular imprinting, perfusion chromatography, the preparation of monolithic separation media as well as to organic HPLC supports prepared by new polymer technologies such as ring-opening metathesis polymerization. Synthetic particularities relevant for the corresponding applications are outlined. 相似文献
Three different synthetic routes to the fourth-generation (G4) macromonomers 4, 6, and 9 for Suzuki polycondensation (SPC) are described and compared in their efficiency. Monomer 9 was selected the best as judged by the number and feasibility of synthetic steps and purification behavior and could be prepared in a 15 g scale. SPC of the monomers 4, 6, and 9 gave the novel poly(para-phenylene)s 17, 18, and 19 with pendant G4 dendrons at every other repeat unit. SPC was optimized for 9 and the diboronic acid ester counterpart 16 which led to polymer 19 with a molecular weight of up to Mn=76,000, Mw=63,9000 (GPC versus polystyrene). High molecular weight is most likely to be obtained for the attempted stoichiometry 9:16 = 1.000:(0.995-1.005). 相似文献