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2021 ◽  
Author(s):  
Jordi Mestre ◽  
Miguel Bernús ◽  
Sergio Castillón ◽  
Omar Boutureira

The introduction of fluoroalkylthioether groups has attracted the attention of the drug discovery community given the special physicochemical and pharmacokinetic features they confer to bioactive compounds. Synthetic advances in the field have been capitalized by methods to incorporate SCF3 and SCF2H motifs, however, longer and synthetically more challenging polyfluoroethyl chains are still underdeveloped. Here, two saccharin-based electrophilic reagents have been disclosed for the efficient incorporation of SCF2CF2H and SCF2CF3 motifs. Their reactivity performance has been thoroughly investigated with a variety of nucleophiles such as thiols, alcohols, amines, alkenes, (hetero)aromatics, and organometallic species, including natural products and pharmaceuticals. Finally, multigram-scale preparation and divergent derivatization has been explored from SCF2CF2H derivatives.


2021 ◽  
pp. 117-131
Author(s):  
Dominic Perring

Roman London was enlarged and enhanced in the years immediately following Vespasian’s accession in ways that corresponded with the known ideological goals of the new Flavian regime. As a consequence the city came to be characterized by an imperial architecture of ‘bread and circuses’. This involved the construction of a new amphitheatre for the conduct of games associated with the imperial cult and as the likely site of public executions. Watermills drawing on the latest engineering technology were installed to allow the large-scale preparation of flour to supply local bakeries. Early Flavian investment also involved the creation of new administrative facilities, perhaps including a mansio in Southwark, and new urban districts allowing military and veteran settlement. Cycles of subsequent investment hint at a correlation between building programmes in London and preparations for new campaigns of advance launched on the arrival of new provincial governors.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 66
Author(s):  
Robert D. Barrows ◽  
Mark J. Dresel ◽  
Thomas J. Emge ◽  
Paul R. Rablen ◽  
Spencer Knapp

The amidation reaction of a tetrahydroisoquinolin-1-one-4-carboxylic acid is a key step in the multi-kilogram-scale preparation of the antimalarial drug SJ733, now in phase 2 clinical trials. In the course of investigating THIQ carboxamidations, we found that propanephosphonic acid anhydride (T3P) is an effective reagent, although the yield and byproducts vary with the nature and quantity of the base. As a control, the T3P reaction of a 3-(2-thienyl) THIQ was performed in the absence of the amine, and the products were characterized: among them are three dimeric allenes and two dimeric lactones. A nucleophile-promoted ketene dimerization process subject to subtle steric and stereoelectronic effects accounts for their formation. Two novel monomeric products, a decarboxylated isoquinolone and a purple, fused aryl ketone, were also isolated, and mechanisms for their formation from the ketene intermediate are proposed.


Author(s):  
Yogesh V. Ushir ◽  
Kundan J. Tiwari

The objective of the present study was to design, development and evaluation antitussive herbal cough syrup because designing of oral herbal formulation is still a challenge in modern pharmaceutics and the syrup formulation presents many technical problems to the industrial pharmacist. Potential antitussive herbs were used for developing the herbal cough syrup. Decoction of plant Anisomeles indica, Leaves of Adhathoda vasika, stems of Glycyrrhiza glabra, fruits of Piper nigrum and plant of Mentha piperita was prepared. One part of decoction was mixed with five parts of simple syrup IP (1:5) to prepare formulation. The formulations were evaluated by morphological characters, physical parameters like PH, Specific gravity, viscosity etc. Herbal cough syrup was also subjected for the accelerated stability testing (AST) for the period of 72hours at accelerated temperature conditions. No marked changes were noticed in all the evaluated parameters during AST. The laboratory scale preparation of herbal Syrup may be used as a stable, liquid dosage form and the work done in stability testing may help in the progress of shelf-life determination studies. The presence study includes design, development and evaluation of Anisomeles indica herbal cough syrup first time.


2021 ◽  
Author(s):  
Wenrui Liu ◽  
Shengjie Xu ◽  
Wuyue Liu ◽  
Xiaozhang Zhu

Despite the development of nonfullerene acceptors (NFAs) that have made a breakthrough in the photovoltaic performance, large-scale preparation of NFAs that is prerequisite for commercial application has never been explored. Herein, we designed two dodecacyclic all-fused-ring electron acceptors, F11 and F13, and develop a whole set of synthetic procedures, achieving unprecedented scalable preparation of NFAs in the lab at a 10-g scale notably within one day. The single-crystal structures of F11 reveals the 3D network packing. F11 and F13 display the lowest costs among reported NFAs, even comparable with the classical donor material, P3HT. By matching a medium-bandgap polymer donor, F13 delivers power conversion efficiencies of over 13%, which is an efficiency record for non-INCN acceptors. Benefiting from the intrinsically high stability, OSCs based on F11 and F13 show device stability superior to the typical ITIC- and Y6-based OSCs as evidenced by the tiny burn-in losses. The current work presents a first example for large-scale preparation of low-cost NFAs with good efficiency and high device stability, which is significant for OSC commercialization in near future.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1513
Author(s):  
Pavol Lopatka ◽  
Michal Gavenda ◽  
Martin Markovič ◽  
Peter Koóš ◽  
Tibor Gracza

This work describes the total synthesis of jaspine B involving the highly diastereoselective Pd(II)-catalysed carbonylative cyclisation in the preparation of crucial intermediates. New conditions for this transformation were developed and involved the pBQ/LiCl as a reoxidation system and Fe(CO)5 as an in situ source of stoichiometric amount of carbon monoxide (1.5 molar equivalent). In addition, we have demonstrated the use of a flow reactor adopting proposed conditions in the large-scale preparation of key lactones.


2021 ◽  
Vol 21 (12) ◽  
pp. 6126-6134
Author(s):  
Lili Chi ◽  
Yuetong Zhang ◽  
Yusheng Hua ◽  
Qiqi Xu ◽  
Mingzhu Lv ◽  
...  

Nanomaterials with intrinsic enzyme-mimicking characteristics, refered to as nanozymes, have become a hot research topic owing to their unique advantages of comparative low cost, high stability and large-scale preparation. Among them, Single-atom nanozymes (SAzymes), as novel nanozymes with abundant atomically dispersed active sites, have caused specific attention in the development of nanozymes for their remarkable catalytic activities, maximum atomic utilization and excellent selectivity, the homogeneous catalytic sites and clear catalytic mechanisms. Herein, a novel single-atom nanozyme based on Fe(III)-doped polydiaminopyridine nanofusiforms (Fe-PDAP SAzyme) was successfully proposed via facile oxidation polymerization strategy. With well-defined coordination structure and abundant Fe-Nx active sites similar to natural metalloproteases, the Fe-PDAP SAzyme exhibits superior peroxidase-like activity by efficiently decomposing H2O2 for hydroxyl radical (.OH) species formation. Based on their superior peroxidase-like activity, colorimetric biosensing of H2O2 and glucose in vitro was performed by using a typical 3,3,5,5-tetramethylbenzidine through a multienzyme biocatalytic cascade platform, exhibiting the superior specificity and sensitivity. This work not only provides a novel promising SAzyme-based biosensor but also paves an avenue for evaluating enzyme activity and broadens the application of other nanozyme-based biosensors in the fields of biomedical diagnosis.


2021 ◽  
pp. 134011
Author(s):  
Gaoming Li ◽  
Yeping Wu ◽  
Zhongtao Chen ◽  
Mao Chen ◽  
Peishuang Xiao ◽  
...  

2021 ◽  
Vol 03 (04) ◽  
pp. e194-e199
Author(s):  
Liang Chen ◽  
Wei-Yuan Liu ◽  
Si-Ju Bi ◽  
Ting Zhou ◽  
Jing Pan ◽  
...  

A series of mono- or bis-quaternary ammonium salts derived from cinchonidine or quinine was synthesized and screened as potent phase-transfer catalysts for the reaction of aza-Michael cyclization, the key step in the synthesis of letermovir. During the reaction of aza-Michael cyclization, the screened monoquaternary ammonium salt quinine derivative Q1 transferred 7 to 8 with 91.9% yield and 58% ee. The application of Q1 was preferred, due to its enantioselectivity, the possibility of reuse, and the lower cost in large-scale preparation. Furthermore, the racemization condition of letermovir enantiomer was also explored for the possibility to develop the resolution/racemization process. With the optimal catalyst Q1 in hand, the synthesis of letermovir may be more convenient and economical in the future.


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