2393-18-2Relevant articles and documents
Ultrahigh performance bio-based polyimides from 4,4′-diaminostilbene
Kumar, Amit,Tateyama, Seiji,Yasaki, Katsuaki,Ali, Mohammad Asif,Takaya, Naoki,Singh, Rajeev,Kaneko, Tatsuo
, p. 182 - 189 (2016/01/09)
We have developed a novel route for the synthesis of high-performance bio-polyimides (PIs) microbially-derived from photo-responsive aromatic diamine 4,4′-diaminostilbene (DAS) and its reduced counterpart 4, 4′-(ethane-1,2-diyl)dianiline (EDDA). DAS and EDDA were condensed with various commercially-available dianhydrides to obtain a series of poly(amic acid)s (PAAs) and PIs which were characterized in terms of their thermal, mechanical, and photo-functions. These bio-based PAAs showed a very high viscosity of 6.62 dL/g, and the PIs showed ultrahigh thermal resistance with Td10 values over 600 °C, which were higher than that of any bio-based plastic reported thus far. They also showed Tg values above 250 °C, and tensile strength of over 132 MPa, which is higher than that of Kapton. The PIs also showed photo-functional behavior based on stilbene-based photoreactions.
A green chemical synthesis of coumarin-3-carboxylic and cinnamic acids using crop-derived products and waste waters as solvents
Fiorito, Serena,Taddeo, Vito Alessandro,Genovese, Salvatore,Epifano, Francesco
supporting information, p. 4795 - 4798 (2016/10/05)
Crop-derived products, like juices obtained from edible fruits and vegetables, and waste waters deriving from agricultural and industrial processing have been recently exploited to efficiently promote several ‘classic’ and innovative synthetic organic reactions. Such a green chemical approach prevented the use of toxic, polluting, and hazardous materials and in the mean time allowed to increase the commercial values of crop products and industrial byproducts. Coumarin-3-carboxylic and cinnamic acids represent classes of naturally occurring and semi-synthetic compounds with interesting and promising pharmacological activities. In this Letter a new and improved methodology for the Knoevenagel condensation yielding the title compounds using juices from edible fruits and vegetables (lemon, grapefruit, carrot, pomegranate, kiwi, vinegar, tomato), liqueurs (limoncello), and waste waters (buttermilk and residues of olive processing) as solvents is described. Coumarin-3-carboxylic and cinnamic acids have been synthesized in excellent yields by ultrasound irradiation from differently substituted 2-hydroxybenzaldehydes, 2-hydroxyacetophenones, and benzaldehydes, and Meldrum's acid as starting substrates. The findings described herein enforce the concept of the usefulness of products and byproducts derived from agriculture and food industry to accomplish green chemical processes.
A facile method for synthesis of amine-functionalized mesoporous zirconia and its catalytic evaluation in Knoevenagel condensation
Parida,Mallick, Sujata,Sahoo,Rana
experimental part, p. 226 - 232 (2010/08/06)
Amine-functionalized mesoporous zirconia was prepared by a co-condensation method using silane (aminopropyltrimethoxysilane, APTES) and zirconium butoxide. The materials were characterized by X-ray diffraction, BET surface area analysis, 13C magic angle spinning-nuclear magnetic resonance (NMR), Fourier-transfer infrared spectroscopy (FTIR), transmittance electron micrography (TEM), and CHN analysis. FTIR and NMR results revealed the successful grafting of organic amines onto the surface of zirconia. The catalytic activities were investigated for liquid phase Knoevenagel condensation of various aromatic aldehydes with diethyl malonate. The catalysts showed excellent yield of products at room temperature in solvent-free condition.
