RSC Advances

doi: 10.1039/c3ra90014bpmid: N/A

doi: 10.1039/c3ra90013dpmid: N/A

Sun, Yin-wei; Zhu, Peng-long; Xu, Qin; Shi, Min

doi: 10.1039/c2ra22674jpmid: N/A

Recent developments on Pd complex-catalyzed asymmetric additions in the last five years have been presented in this context. As can be seen from this paper, lots of Pd complex-catalyzed asymmetric reactions have been reported in last five years. The Pd-catalyzed asymmetric additions of CX bonds (X = C, O, N) with various nucleophiles including boronic acids are very efficient and highly stereoselective under mild conditions. These type reactions have been developed into well-established methods for the stereoselective construction of carbon–carbon and carbon–heteroatom bonds in organic synthesis.

Seok Jeong, Doo; Kim, Inho; Ziegler, Martin; Kohlstedt, Hermann

doi: 10.1039/c2ra22507gpmid: N/A

We overview several efforts to emulate functionalities of basic building blocks, i.e. neurons and synapses, of a mammal’s brain by means of non-biological inorganic systems. These efforts have been put to realize ambitious goals such as the achievement of artificial inorganic brains on silicon wafers, i.e. neuromorphic systems, and neuroprosthetic systems taking part in real brain functionalities by interfacing with real brains. In terms of the keywords, ‘threshold’, ‘analogue’, ‘plasticity’, and ‘elasticity’, which describe the behaviour of neurons and synapses, various functional systems, with particular emphasis on nanoionic systems, exhibiting these key behaviours, are dealt with in this review.

Satasia, Shailesh P.; Kalaria, Piyush N.; Raval, Dipak K.

doi: 10.1039/c3ra23052jpmid: N/A

The synthesis of a novel cellulose supported acidic ionic liquid (Cell-IL) for the solvent-free synthesis of hydroxylated trisubstituted pyridines is reported. Cell-IL was prepared by immobilization of an acidic ionic liquid [1-butyl-3-(3-trimethoxypropyl)-1H-imidazol-3-ium hydrogen sulfate] on cellulose. The viability of this concept has been confirmed by FT-IR, TGA-DTG, 1H NMR and elemental analysis. The Cell-IL showed good thermal stability and exhibited a high catalytic activity in the synthesis of a series of hydroxylated trisubstituted pyridines. It was recovered and reused for the model reaction three times without an appreciable change in its activity.

Mitra, Shouvik; Chandra, Sourov; Pathan, Shaheen H.; Sikdar, Narattam; Pramanik, Panchanan; Goswami, Arunava

doi: 10.1039/c2ra23085bpmid: N/A

Highly fluorescent, self passivated carbon quantum dots (CQDs) have been synthesized using PEG-200 at room temperature for the first time followed by solvothermal modification to increase the quantum yield of these nano carbons. At elevated temperature and pressure good surface passivation has been observed. No sophisticated instrument nor passivating agent is required to fabricate these CQDs, making the procedure unique and novel with respect to all the existing protocols. Solvothermally synthesized carbon quantum dots (ST-CQDs) exhibited minimum toxicity and can be used easily for bioimaging.

Kim, Dongjin; Hong, Seungbum; Li, Dongjun; Roh, Hee Seok; Ahn, Gun; Kim, Jiyoon; Park, Moonkyu; Hong, Jongin; Sung, Tae-hyun; No, Kwangsoo

doi: 10.1039/c2ra22554apmid: N/A

We developed a three-dimensional spring-type piezoelectric energy harvester using a dip-coating method and multi-directional electrode deposition. The energy harvester consists of a bi-layered structure composed of a surface electrode and a ferroelectric polymer, on a conventional spring which has two roles – the core electrode and the mechanical substrate for the ferroelectric polymer. The energy harvester generated an output voltage of up to 88 mV as a function of cycling compression stress, which leads to a piezoelectric constant of 28.55 pC N−1 for unpoled P(VDF-TrFE) films. Since the spring structure significantly decreases the resonance frequency of the harvester, the spring-type energy harvester can effectively generate electricity using low-frequency vibration energy abundant in the nature.

Tamilarasan, S.; Sarma, Debajit; Reddy, M. L. P.; Natarajan, S.; Gopalakrishnan, J.

doi: 10.1039/c2ra22400cpmid: N/A

A purple inorganic pigment, YGa1−xMnxO3 (0 < x ≤ 0.10), based on hexagonal YGaO3 is reported here. The metastable series of oxides were prepared by a sol–gel technique where the dried gels, obtained from aqueous solutions of metal nitrate–citric acid mixtures, were calcined for a short duration in a preheated furnace around 850 °C. The purple colour of the oxides arises from the specific trigonal bipyramidal ligand field around MnIII in a YGaO3 host. Other hexagonal RGaO3 hosts for R = Lu, Tm and Ho substituted with MnIII also produce similar purple coloured materials.

Bhattacharyya, Pranabes; Paul, Sanjay; Das, Asish R.

doi: 10.1039/c3ra23254apmid: N/A

A highly convergent and efficient protocol, for the facile synthesis of a library of coumarin fused pyridine and pyridopyrimidine derivatives, has been developed by applying a Lewis base-surfactant-combined catalyst (LBSC) triethanolamine (TEOA). The method described has the benefits of operational simplicity and excellent yields of the targeted molecule. The LBSCs were found to form stable colloidal dispersions rapidly in the presence of reaction substrates in water, even when the substrates are solid. In light of the increased demand for reduction of organic solvents in industry, the surfactant aided Lewis base catalysis described here may have immense practical consequences in organic synthesis. This work may not only lead to environmentally benign systems but also will provide a newer aspect of organic chemistry in water.

Reichau, Sebastian; Parker, Emily J.

doi: 10.1039/c3ra00037kpmid: N/A

3-Deoxy-d-arabino-heptulosonate 7-phosphate synthase is an important biosynthetic enzyme in Mycobacterium tuberculosis and a potential drug target. We describe the synthesis, evaluation and docking of inhibitors with various chain lengths, which provide insight into the plasticity of the active site for inhibitor binding.