1472-85-1Relevant articles and documents
Synthesis and Solution Properties of a Double-Tailed Quaternary Ammonium Surfactant with a Protrudent Head Group
Song, Binglei,Xu, Zonghui,Yu, Xiaona,Chen, Shuyi,Li, Shunan,Shi, Rongzhen,Cui, Zhenggang
, p. 1081 - 1088 (2015)
Modification of the molecular structure of surfactants is an effective method for exploring their self-assembly. A double-tailed quaternary ammonium surfactant with a protrudent head group, namely 2-octyldecyltrimethylammonium bromide (2-ODTAB) was synthesized, and the solution properties were investigated by surface tension, dynamic light scattering, and cryogenic TEM. A comparative study was also performed on the traditional double-tailed homologue surfactants dioctyldimethylammonium bromide (8-8), didecyldimethylammonium bromide (10-10), and didodecyldimethylammonium bromide (12-12). The results showed that 2-ODTAB was more effective at lowering surface tension and in forming stable vesicles than traditional double-tailed surfactants with similar alkyl chain length. The reason is attributed to the improved structure of 2-ODTAB, in which the two alkyl tails are connected to the ionic head group by one carbon atom. This structure imparts more freedom to the head group and thus favors formation of more stable aggregates at low concentration. In addition, the lower limit of the alkyl chain length of the double-tailed surfactants for forming stable vesicles was illustrated.
Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)
Condon, Sylvie,Le Gall, Erwan,Pichon, Christophe,Presset, Marc,Xavier, Tania
supporting information, p. 2085 - 2094 (2021/09/02)
The use of mono-substituted malonic acid half oxyesters (SMAHOs) has been hampered by the sporadic references describing their preparation. An evaluation of different approaches has been achieved, allowing to define the best strategies to introduce diversity on both the malonic position and the ester function. A classical alkylation step of a malonate by an alkyl halide followed by a monosaponification gave access to reagents bearing different substituents at the malonic position, including functionalized derivatives. On the other hand, the development of a monoesterification step of a substituted malonic acid derivative proved to be the best entry for diversity at the ester function, rather than the use of an intermediate Meldrum acid. Both these transformations are characterized by their simplicity and efficiency, allowing a straightforward access to SMAHOs from cheap starting materials.
Synthesis of protected α-amino acids: Via decarboxylation amination from malonate derivatives
Dai, Qipu,Fu, Hui,Hu, Changwen,Li, Peihe,Li, Xiaoying,Wang, Zheng
, p. 4439 - 4446 (2020/10/20)
A general and efficient strategy for the synthesis of protected α-amino acids is reported. The method uses malonate derivatives as the starting materials and Cs2CO3 as a base at 60 degrees, giving α-amino acid derivatives in moderate yields by releasing CO2. This methodology shows broad substrate scope (primary and secondary acids), excellent functional group tolerance and high efficiency to give the desired products under mild reaction conditions. It also allows the construction of β and γ-amino acids and other unnatural products.
Metal-Organic Framework Anchored with a Lewis Pair as a New Paradigm for Catalysis
Niu, Zheng,Bhagya Gunatilleke, Wilarachchige D.C.,Sun, Qi,Lan, Pui Ching,Perman, Jason,Ma, Jian-Gong,Cheng, Yuchuan,Aguila, Briana,Ma, Shengqian
, p. 2587 - 2599 (2018/12/02)
Lewis pair (LP) chemistry has shown broad applications in the catalysis field. However, one significant challenge has been recognized as the instability for most homogeneous LP catalysts upon recycling, thus inevitably leading to dramatic loss in catalytic activity. Additionally, current heterogeneous LP catalysts suffer from low surface area, which largely limits their catalytic efficiency, thereby restricting their potential applications. In this work, we report the successful introduction of LPs, classical and frustrated, into a metal-organic framework (MOF) that features high surface and ordered pore structure via a stepwise anchoring strategy. Not only can the LP be stabilized by the strong coordination interaction between the LP and MOF, but the resultant MOF-LP also demonstrates excellent catalysis performance with interesting size and steric selectivity. Given the broad applicability of LPs, our work therefore paves a way for advancing MOF-LP as a new paradigm for catalysis. Lewis pairs (LPs), classical and frustrated, are excellent prospects in catalysis, organic syntheses, biology, and material sciences. However, the instability of most LP catalysts leads to a dramatic loss in activities, thereby largely restricting their industrial applications. As robust porous materials, metal-organic frameworks (MOFs) offer a platform to stabilize homogeneous catalysts. Here, we show a strategy that grafts the LP catalyst on the MOF to minimize loss of LPs during catalysis and recycling. Our work reveals the enormous potential of MOFs as an appealing paradigm for the construction of efficient heterogeneous catalysts with interesting steric and size selectivity worthy of exploration. In addition, the strategies for anchoring a LP into a MOF as contributed herein can be readily applied for the task-specific design of functional catalysis materials for various applications. Lewis pairs (LPs), classical and frustrated, have been successfully introduced into and stabilized in a metal-organic framework (MOF). Benefiting from the robust framework and tunable porous structure of MOFs, the resultant MOF-LP demonstrates not only great recyclability but also excellent performance in the catalytic reduction of imines and hydrogenation of alkenes. The combination of LP and MOF therefore lays a foundation for developing a MOF-LP as a new paradigm for catalysis, particularly heterogeneous catalysis.
