105591-47-7Relevant academic research and scientific papers
Synthesis of Self-Healing Polymers by Scandium-Catalyzed Copolymerization of Ethylene and Anisylpropylenes
Wang, Haobing,Yang, Yang,Nishiura, Masayoshi,Higaki, Yuji,Takahara, Atsushi,Hou, Zhaomin
, (2019/02/19)
Self-healing materials are of fundamental interest and practical importance. Herein we report the synthesis of a new class of self-healing materials, formed by the copolymerization of ethylene and anisyl-substituted propylenes using a sterically demanding half-sandwich scandium catalyst. The copolymerization proceeded in a controlled fashion, affording unique multi-block copolymers composed of relatively long alternating ethylene-alt-anisylpropylene sequences and short ethylene-ethylene units. By controlling the molecular weight and varying the anisyl substituents, a series of copolymers that show a wide range of glass-transition temperatures (Tg) and mechanical properties have been obtained. The copolymers with Tg below room temperature showed high elastic modulus, high toughness, and remarkable self-healability, being able to autonomously self-heal upon mechanical damage not only in a dry environment but also in water and aqueous acid and alkaline solutions, while those with Tg around or above room temperature exhibited excellent shape-memory property. The unique mechanical properties may be ascribed to the phase separation of the crystalline ethylene-ethylene nanodomains from the ethylene-alt-anisylpropylene matrix.
A natural-product switch for a dynamic protein interface
Scheepstra, Marcel,Nieto, Lidia,Hirsch, Anna K.H.,Fuchs, Sascha,Leysen, Seppe,Lam, Chan Vinh,In Het Panhuis, Leslie,Van Boeckel, Constant A.A.,Wienk, Hans,Boelens, Rolf,Ottmann, Christian,Milroy, Lech-Gustav,Brunsveld, Luc
, p. 6443 - 6448 (2014/06/24)
Small ligands are a powerful way to control the function of protein complexes via dynamic binding interfaces. The classic example is found in gene transcription where small ligands regulate nuclear receptor binding to coactivator proteins via the dynamic activation function 2 (AF2) interface. Current ligands target the ligand-binding pocket side of the AF2. Few ligands are known, which selectively target the coactivator side of the AF2, or which can be selectively switched from one side of the interface to the other. We use NMR spectroscopy and modeling to identify a natural product, which targets the retinoid X receptor (RXR) at both sides of the AF2. We then use chemical synthesis, cellular screening and X-ray co-crystallography to split this dual activity, leading to a potent and molecularly efficient RXR agonist, and a first-of-kind inhibitor selective for the RXR/coactivator interaction. Our findings justify future exploration of natural products at dynamic protein interfaces.
Selective Demethylative Cyclisation of 2-Methoxy-allylbenzenes
Devakumar, C.,Mukerjee, S. K.
, p. 368 - 372 (2007/10/02)
Treatment of 3-substituted 2-methoxyallylbenzenes with dry HBr in CHCl3 causes selective demethylative cyclisation to give 7-substituted 2-methyl-2,3-dihydrobenzofurans.The reaction involves mutual participation of allyl and 2-methoxyl groups and is sterically accelerated by substituents vicinal to OCH3.The reaction does not take place in high dielectric solvents such as DMF or DMSO.A propable mechanism envisaging a non-classical ionic transition state is proposed and the synthetic utility of this reaction is also demonstrated.
