作者:Pietro Tundo、Fabio Aricò、Guillaume Gauthier、Laura Rossi、Anthony E. Rosamilia、Hanamanthsa S. Bevinakatti、Robert L. Sievert、Christoper P. Newman
DOI:10.1002/cssc.201000011
日期:——
A green synthetic approach for dimethylisosorbide (DMI) with dimethylcarbonate (DMC) in the presence of a base is reported. The easy methylation of isosorbide may be due to its unique structure (which enhances the nucleophilicity of the hydroxyl groups), and to the effect of the hydrogen bonding which increases the reactivity of the molecule towards DMC.
Efficient synthesis of bio-derived polycarbonates from dimethyl carbonate and isosorbide: regulating <i>exo</i>-OH and <i>endo</i>-OH reactivity by ionic liquids
imbalance reactivity of exo-OH and endo-OH in isosorbide. Moreover, these ILs exclusively activate the carbonyl carbon of DMC for accelerating the polymerization reaction. These features are appealing superiorities of ILs as compared to catalysts involving metallic elements. The [Emim]Br catalyst remarkably decreased the imbalanced reactivity of –OH groups of isosorbide, and exhibited the highest catalytic
设计用于使用CO 2,基于CO 2的化合物或生物可再生化学品作为构建基块来合成高分子量聚碳酸酯的催化剂是一个巨大的挑战。为此,已经开发了一种生态兼容的方法,可从生物可再生的异山梨醇和CO 2衍生的碳酸二甲酯(DMC)合成聚碳酸酯:可通过改变离子液体的阳离子结构来调节聚异山梨醇碳酸酯的分子量(IL)催化剂。可以通过调节阳离子结构来改变离子分子的氢键给定和接受能力,从而成功地实现了外-OH和内-基的内在失衡反应性的可调性。-OH在异山梨醇中。而且,这些ILs专门活化DMC的羰基碳以加速聚合反应。与涉及金属元素的催化剂相比,这些特征是IL的吸引人的优势。[Emim] Br催化剂显着降低了异山梨醇的-OH基团的不平衡反应性,并显示出最高的催化活性。在[Emim] Br的存在下,获得的聚(碳酸异山梨酯)(PIC)的重均分子量和玻璃化转变温度分别为52 100 g mol -1和156℃。此外,根据实验结果,DFT计算和原位11
作者:Mattia Annatelli、Davide Dalla Torre、Manuele Musolino、Fabio Aricò
DOI:10.1039/d1cy00465d
日期:——
Dimethylisosorbide (DMI) is a well-known bio-based green replacement for conventional dipolar solvents such as dimethyl sulfoxide and dimethylformamide. The synthesis of DMI mainly relies on the etherification of the bio-based platform chemical isosorbide in the presence of basic or acid catalysts and by employing different alkylating agents. Among them, dimethyl carbonate (DMC) is considered one
Greensynthesis of high‐molecular‐weight isosorbide‐based polycarbonate (PIC) with excellent properties is a tremendous challenge and is profoundly influenced by the precursor. Herein, an ecofriendly catalyst was employed to obtain the more reactive PIC precursor dicarboxymethyl isosorbide (DC) with 99.0 % selectivity through the transesterification reaction of isosorbide with dimethyl carbonate. This
The synthesis of high-molecular-weight bioderived polycarbonates via green routes and regulation of molecular weight is of great significance and is highly challenging. Herein, a green sequential approach toward the synthesis of bio-derived polycarbonates with adjustable molecular weights from isosorbide and dimethyl carbonate (DMC) has been developed by employing ionicliquids (ILs) as a class of
通过绿色路线和分子量调节来合成高分子量生物衍生的聚碳酸酯具有重要意义并且具有很高的挑战性。本文中,已经通过采用离子液体(IL)作为一类生态友好型催化剂,开发了一种绿色连续方法,用于从异山梨醇和碳酸二甲酯(DMC)合成分子量可调节的生物衍生聚碳酸酯。IL催化剂的结构可以容易地设计以控制异山梨醇衍生的聚碳酸酯(PIC)的分子量,这是IL催化剂代替常规的含金属催化剂的吸引人的优点。在[Bmim] [4-I-Phen]催化剂的存在下,PIC重均分子量(M w)可以达到50 300 g mol-1。通过实验结果和DFT计算的结合,提出了一种IL阴离子-阳离子协同催化聚合机理,该机理揭示了H-键亲核体-亲电子体双重活化以及电荷-电荷相互作用对PIC形成的催化作用。这项研究的意义在于,它为开发用于合成更高分子量聚碳酸酯的IL催化剂提供了指导,从而方便地生产出各种具有可调性的聚合物。