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111.
Ghulam Bary Muhmmad Imran Jamil Muhammad Arslan Lubna Ghani Waqar Ahmed Haseen Ahmad Gohar Zaman Khurshid Ayub Muhammad Sajid Riaz Ahmad Duohui Huang Futi Liu Yue Wang 《Journal of Saudi Chemical Society》2021,25(7):101260
Alkene is an attractive substrate for chemists due to its easy availability and reactivity towards large number of reactants affording diverse range of organic compounds. It reacts under ionic and free radical mechanisms including single electron transfer (SET). In this review, strategies used for C–C and C-heteroatom functionalization of alkene has been discussed with emphasis on the regio, stereoselectivity, mechanistic detail and sustainability aspects. These strategies mainly follow the free radical mechanism, and the highly reactive carbon radicals show uncontrollable regio- and stereoselectivities. Thus these strategies still need to be focused; especially in the asymmetric versions. The regio- and stereoselectivities of functionalization of alkenes have been highlighted and debated. In addition, the hazardous reagents such as Cl2, Br2 I2, CO, peroxides, and benzene have also been discussed with the emphasis on their impact on the environment. Their plausible green alternatives have also been suggested, such as MX as halogen replacement; CO surrogates (formaldehyde etc.); sustainable aromatic solvents as benzene replacement. The non-green strategies relying on pre-formed silyl hydride and their green alternative strategies such as transfer hydrogenations have also been indicated. The applications of the functionalization of alkenes for the total synthesis of bioactive compounds have also been discussed in detail. In addition, future perspectives are also highlighted for further developments in the functionalization of alkenes. 相似文献
112.
When Cl2NCF2CF2NCl2 is heated with CF2CFX (X = Cl, F) ClXCFCF2N(Cl)CF2CF2N(Cl)CF2CXClF (X = Cl, 2 ; F, 3 ) is formed. Mercury extracts chlorine fluoride from 2 and 3 to form new polyfluorobisazomethines, ClXCFCF2NCFCFNCF2CXClF (X = Cl, 4 ; F, 5 ). Photolysis of the product obtained from CCl2NCCl2CCl2NCCl2 with ClF, CF2ClN(Cl)CF ClCFClN(Cl)CF2Cl ( 6 ) gives another bisazomethine, CF2ClNCFCFNCF2Cl ( 7 ) with concomitant loss of Cl2. At 25°C, in the presence of CsF, 4 and 5 are cyclized to give (X = Cl, 8 ; F, 9 ), and 7 forms a bicyclic derivative at 100°C, ( 1 ). Addition of chlorine fluoride to 8 and to 1 produces ( 10 ) and ( 14 ), respectively. Photolysis of 10 results in the loss of CFCl3 to form ( 11 ), and 14 loses Cl2 and dimerizes to the hydrazine ( 15 ). The further addition of ClF to 11 gives rise to ( 12 ) which when photolyzed at 3000 Å forms a second cyclic hydrazine, ( 13 ). 相似文献
113.
114.
Bismillah Mubeen Mahvish Ghulam Rasool Inam Ullah Rabia Rasool Syed Sarim Imam Sultan Alshehri Mohammed M. Ghoneim Sami I. Alzarea Muhammad Shahid Nadeem Imran Kazmi 《Molecules (Basel, Switzerland)》2022,27(4)
Engineered nanoparticles that have distinctive targeted characteristics with high potency are modernistic technological innovations. In the modern era of research, nanotechnology has assumed critical importance due to its vast applications in all fields of science. Biologically synthesized nanoparticles using plants are an alternative to conventional methods. In the present study, Citrullus colocynthis (bitter apple) was used for the synthesis of gold nanoparticles (AuNPs). UV-Vis’s spectroscopy, XRD, SEM and FTIR were performed to confirm the formation of AuNPs. UV-Vis’s spectra showed a characteristic peak at the range of 531.5–541.5 nm. XRD peaks at 2 θ = 38°, 44°, 64° and 77°, corresponding to 111, 200, 220 and 311 planes, confirmed the crystalline nature of AuNPs. Spherical AuNPs ranged mostly between 7 and 33 nm, and were measured using SEM. The FTIR analysis confirmed the presence of phytochemicals on the surface of AuNPs. Successful synthesis of AuNPs by seed extract of Citrullus colocynthis (bitter apple) as a capping and reducing agent represents the novelty of the present study. 相似文献
115.
郭子溢 Lars Bathe-Peters 陈少敏 Mourad Chouaki 窦威 郭磊 Ghulam Hussain 李进京 刘倩 罗光 骆文泰 祁鸣 邵文辉 唐健 万林焱 王喆 续本达 徐彤 徐蔚然 杨玉梓 Minfang Yeh 赵林 《中国物理C(英文版)》2021,(2):509-517
China Jinping Underground Laboratory(CJPL)is ideal for studying solar,geo-,and supernova neutrinos.A precise measurement of the cosmic-ray background is essential in proceeding with R&D research for these MeV-scale neutrino experiments.Using a 1-ton prototype detector for the Jinping Neutrino Experiment(JNE),we detected 264 high-energy muon events from a 645.2-day dataset from the first phase of CJPL(CJPL-I),reconstructed their directions,and measured the cosmic-ray muon flux to be (3.53±0.22_stat.±0.07_sys.)×-10-10cm-2.The observed angular distributions indicate the leakage of cosmic-ray muon background and agree with simulation data accounting for Jinping mountain's terrain.A survey of muon fluxes at different laboratory locations,considering both those situated under mountains and those down mine shafts,indicates that the flux at the former is generally a factor of (4±2) larger than at the latter,with the same vertical overburden.This study provides a convenient back-of-the-envelope estimation for the muon flux of an underground experiment. 相似文献
116.
Sharma Vivek Das Dipak Kumar Vashistha Vinod Kumar Gupta Ram K. Yasin Ghulam Kumar Anuj 《Journal of inclusion phenomena and macrocyclic chemistry》2022,102(5-6):477-485
Journal of Inclusion Phenomena and Macrocyclic Chemistry - Due to the sluggish nature of the oxygen reduction reaction (ORR), it requires electro-catalysts to speed up the kinetics of ORR at a... 相似文献
117.
Ghulam Mohmad Subhajit Sarkar Ashmita Biswas Kingshuk Roy Dr. Ramendra Sundar Dey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(55):12664-12673
The design and synthesis of metal-free catalysts with superior electrocatalytic activity, high durability, low cost, and under mild conditions is extremely desirable but remains challenging. To address this problem, a polymer-assisted electrochemical exfoliation technique of graphite in the presence of an aqueous acidic medium is reported. This simple, cost-effective, and mass-scale production approach could open the possibility for the synthesis of high-quality nitrogen-doped graphene–polypyrrole (NG-PPy). The NG-PPy catalyst displays an improved half wave potential (E1/2=0.77 V) in alkaline medium compared with G-PPy (E1/2=0.66 V). Most importantly, this catalyst demonstrates excellent stability with high methanol tolerance, and it outperforms the commercial Pt/C catalyst and other previously reported metal-free catalysts. The content of graphitic nitrogen atoms is the key factor for the enhancement of electrocatalytic activity towards oxygen reduction reactions (ORR). Interestingly, the NG-PPy catalyst can be used as a cathode material in a zinc–air battery, which demonstrates a higher peak power density (59 mW cm−2) than G-PPy (36.6 mW cm−2), highlighting the importance of the low-cost material synthesis approach towards the development of metal-free efficient ORR catalysts for fuel cell and metal–air battery applications. Remarkably, the polymer-assisted electrophoretic exfoliation of graphite with a high yield (≈88 wt %) of few-layer graphene flakes could pave the way towards the mass production of high-quality graphene for a variety of applications. 相似文献
118.
In the present experimental work, oscillator strengths of the 4s5s 3S1 → 4snp 3Po2 (18?≤?n?≤?53) Rydberg transitions of zinc are reported. The stepwise laser excitation from the ground state 4s2 1S0 was achieved using three dye laser beams simultaneously pumped by the second (532?nm) and third (355?nm) harmonics of a Q-switched Nd: YAG (Neodymium-doped yttrium aluminum garnet) laser. The vapor containment and detection system was a single wire thermionic diode ion detector operating in space charge limited mode. A trend of the above-mentioned f-values from n?=?18 to 53 versus the principle quantum number n has been presented. Furthermore, continuity has been verified between the discrete f-values and the oscillator strength density at the threshold. 相似文献
119.
Faisal Khan Arslan Ali Ayesha Iqbal Syed Ghulam Musharraf 《Biomedical chromatography : BMC》2020,34(3):e4753
Advancements in proteomic tools offer a comprehensive solution to studying the complexity of diseases at molecular level. This study focusses on the clinical proteomic profiling of pre- and post-hydroxyurea (HU)-treated β-thalassemia patients in parallel with healthy individuals to better understand the role of HU in the treatment of β-thalassemia. The strategy encompasses sequential high-resolution protein fractionation using MicroSol-isoelectric focusing (ZOOM- IEF) followed by one-dimensional SDS-PAGE before nano-RP-LC–MS/ MS analysis of tryptic peptides. Protein identification was performed through Mascot search using NCBInr and SwissProt databases. Several different proteins were observed in pool serum samples of each of the three study groups. Approximately, 1250 proteins exclusive to each group were identified, and after removing the redundant and low sequence coverage proteins, the number was reduced to 576 (201 in healthy, 187 in HU-untreated and 188 in HU-treated group). Uniquely identified proteins in the HU-treated group regulate the focal adhesion, ECM-receptor interaction, PI3K-Akt signaling, Rap1 signaling, cAMP signaling, platelet activation, and Ca2+ signaling pathways in the HU-treated group. The proteomic profile presented here will add to the current state of understanding of molecular mechanisms involved in hydroxyurea treatment of β-thalassemia. 相似文献
120.
Selvanathan Vidhya Yahya Rosiyah Shahiduzzaman Md Ruslan Mohd. Hafidz Muhammad Ghulam Amin Nowshad Akhtaruzzaman Md. 《Cellulose (London, England)》2021,28(9):5545-5557
Cellulose - Starch and cellulose have long been used in various industrial applications as gelating agents. In this work, the intrinsic adhesive properties of these biopolymers are exploited for... 相似文献