A new strategy to achieve sequence control in polymer chemistry based on the iterative application of the versatile Passerini three‐component reaction (P‐3CR) in combination with efficient thiol–ene ...addition reactions is introduced. First, stearic acid was used as a starting substrate to build up a sequence‐defined tetramer with a molecular weight of 1.6 kDa. Using an acid‐functionalized PEG allowed for an easier isolation of the sequence‐defined macromolecules by simple precipitation and led to a sequence‐defined pentamer in a block‐copolymer architecture. Importantly, this new strategy completely avoids protecting group chemistry. By following this strategy, a different side chain can be introduced to the polymer/oligomer backbone in a simple way and at a defined position within the macromolecule.
The iterative application of the Passerini three‐component reaction and the thiol–ene addition reaction provides sequence‐defined macromolecules without the utilization of any protecting group.
A novel and straightforward one‐pot multicomponent polycondensation method was established in this work. The Biginelli reaction is a versatile multicomponent reaction of an aldehyde, a β‐ketoester ...(acetoacetate) and urea, which can all be obtained from renewable resources, yielding diversely substituted 3,4‐dihydropyrimidin‐2(1H)‐ones (DHMPs). In this study, renewable diacetoacetate monomers with different spacer chain lengths (C3, C6, C10, C20) were prepared via simple transesterification of renewable diols and commercial acetoacetates. The diacetoacetate monomers were then reacted with renewable dialdehydes, i.e., terephthalaldehyde and divanillin in a Biginelli type step‐growth polymerization. The obtained DHMP polymers (polyDHMPs) displayed high molar masses, high glass transition temperatures (Tg) up to 203 °C and good thermal stability (Td5%) of 280 °C. The Tg of the polyDHMPs could be tuned by variation of the structure of the dialdehyde or the diacetoacetate component.
A novel and straightforward multicomponent one‐pot Biginelli polycondensation employing urea, dialdehydes, and diacetoaceates as AA‐type monomers is reported. The resulting Biginelli‐type polymers (polyDHMPs) display high glass transition temperatures (Tg) up to 203 °C. Furthermore, the Tg can be tuned by variation of the components and all monomers used for the polymerizations can be obtained from renewable resources.
Taking advantage of the structural diversity of different biomass resources, recent efforts were directed towards the synthesis of renewable monomers and polymers, either for the substitution of ...petroleum‐based resources or for the design of novel polymers. Not only the use of biomass, but also the development of sustainable chemical approaches is a crucial aspect for the production of sustainable materials. This review discusses the recent examples of chemical modifications and polymerizations of abundant biomass resources with a clear focus on the sustainability of the described processes. Topics such as synthetic methodology, catalysis, and development of new solvent systems or greener alternative reagents are addressed. The chemistry of vegetable oil derivatives, terpenes, lignin, carbohydrates, and sugar‐based platform chemicals was selected to highlight the trends in the active field of a sustainable use of renewable resources.
Going green! Recent developments in the sustainable use of vegetable oil derivatives, terpenes, lignin, carbohydrates, and sugar‐based platform chemicals for the synthesis of renewable monomers and polymers are highghted in this Minireview.
Plant oils and their derived fatty acids are a highly valuable renewable resource for polymer science. In this review, the use of this renewable resource for the synthesis of nitrogen‐containing ...step‐growth polymers, that is, polyamides and polyurethanes, is described. The focus is on the accessible structures of monomers and polymers and thus also the obtainable polymer properties. More importantly, the sustainability of the approaches is discussed and compared to each other where possible, also giving suggestions for future developments.
The nitrogen makes the difference: the use of plant oils for the synthesis of nitrogen‐containing renewable step‐growth polymers, i.e., polyamides and polyurethanes, is summarized and evaluated in terms of sustainability.
Already for a long time, plant oils and their derivatives have been used by polymer chemists due to their renewable nature, world wide availability, relatively low price, and their rich application ...possibilities. Although many different synthetic approaches have been used, more recent examples are pointing in the direction of catalytic transformations and other efficient reactions to achieve a more sustainable production of polymers from these renewable resources. In this context, olefin metathesis, thiol–ene additions, and other processes can contribute not only to a more efficient synthesis of plant oil based polymers, but also to broaden the application possibilities of plant oils. This feature article provides an overview of the present situation with special attention to the use of olefin metathesis and thiol–ene chemistry as synthetic methods and as polymerization techniques.
Oils and fats of vegetable and animal origin have been the most important renewable feedstock of the chemical industry in the past and in the present. A tremendous geographical and feedstock shift of ...oleochemical production has taken place from North America and Europe to southeast Asia and from tallow to palm oil. It will be important to introduce and to cultivate more and new oil plants containing fatty acids with interesting and desired properties for chemical utilization while simultaneously increasing the agricultural biodiversity. The problem of the industrial utilization of food plant oils has become more urgent with the development of the global biodiesel production. The remarkable advances made during the last decade in organic synthesis, catalysis, and biotechnology using plant oils and the basic oleochemicals derived from them will be reported, including, for example, ω‐functionalization of fatty acids containing internal double bonds, application of the olefin metathesis reaction, and de novo synthesis of fatty acids from abundantly available renewable carbon sources.
More than just a greasy spoon: Oils and fats are the most important renewable feedstock of the chemical industry. Recent and exciting advances in chemistry and biotechnology were made within the last 10 years concerning their utilization as a chemical feedstock. This progress in organic synthesis, catalysis, and biotechnology using plant oils and their derivatives is highlighted.
A convenient and inherently more secure communication channel for encoding messages via specifically designed molecular keys is introduced by combining advanced encryption standard cryptography with ...molecular steganography. The necessary molecular keys require large structural diversity, thus suggesting the application of multicomponent reactions. Herein, the Ugi four-component reaction of perfluorinated acids is utilized to establish an exemplary database consisting of 130 commercially available components. Considering all permutations, this combinatorial approach can unambiguously provide 500,000 molecular keys in only one synthetic procedure per key. The molecular keys are transferred nondigitally and concealed by either adsorption onto paper, coffee, tea or sugar as well as by dissolution in a perfume or in blood. Re-isolation and purification from these disguises is simplified by the perfluorinated sidechains of the molecular keys. High resolution tandem mass spectrometry can unequivocally determine the molecular structure and thus the identity of the key for a subsequent decryption of an encoded message.
The efficient synthesis of a sequence‐defined decamer, its characterization, and its straightforward dimerization through self‐metathesis are described. For this purpose, a monoprotected AB monomer ...was designed and used to synthesize a decamer bearing ten different and selectable side chains by iterative Passerini three‐component reaction (P‐3CR) and subsequent deprotection. The highly efficient procedure provided excellent yields and allows for the multigram‐scale synthesis of such perfectly defined macromolecules. An olefin was introduced at the end of the synthesis, allowing the self‐metathesis reaction of the resulting decamer to provide a sequence‐defined 20‐mer with a molecular weight of 7046.40 g mol−1. The obtained oligomers were carefully characterized by NMR and IR spectroscopy, GPC and GPC coupled to ESI‐MS, and mass spectrometry (FAB and orbitrap ESI‐MS).
Cleary defined: A sequence‐defined decamer with ten different and selectable side chains can be synthesized efficiently (yield of each reaction step >90 %), also on a larger scale, and with simple workup procedures. Functional groups were installed at the side chains allowing for further modification. The self‐metathesis reaction of the sequence‐defined decamer led to a sequence‐defined 20‐mer with a molecular weight of more than 7 kDa.
This review describes different synthetic strategies towards sequence‐defined, monodisperse macromolecules, which are built up by iterative approaches and lead to linear non‐natural polymer ...structures. The review is divided in three parts: solution phase‐, solid phase‐, and fluorous‐ and polymer‐tethered approaches. Moreover, synthesis procedures leading to conjugated and non‐conjugated macromolecules are considered and discussed in the respective sections. A major focus in the evaluation is the applicability of the different approaches in polymer chemistry. In this context, simple procedures for monomer and oligomer synthesis, overall yields, scalability, purity of the oligomers, and the achievable level of control (side‐chains, backbone, stereochemistry) are important benchmarks.
A review of synthesis procedures leading to monodisperse and sequence‐defined linear macromolecules, including conjugated and non‐conjugated oligomers, is presented. The approaches are summarized and analyzed in terms of applicability in polymer science. Simple synthesis procedures, scales, overall yields, achievable level of control, and the purity of the obtained macromolecules are important benchmarks.
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