Single-step conversion of silathiogermylene to germaacid anhydrides: unusual reactivity

2015 ◽  
Vol 51 (20) ◽  
pp. 4310-4313 ◽  
Author(s):  
Surendar Karwasara ◽  
Dhirendra Yadav ◽  
Chandan Kumar Jha ◽  
Gopalan Rajaraman ◽  
Selvarajan Nagendran

Single-step conversion of germylene (2) to germaacid anhydrides (3 and 4) is achieved through oxidative-addition with S/Se that involves condensation for the first time.

2017 ◽  
Vol 15 (10) ◽  
pp. 2163-2167 ◽  
Author(s):  
Zhouting Rong ◽  
Antonio M. Echavarren

The polycyclisation of polyeneynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon–carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings.


2016 ◽  
Vol 12 ◽  
pp. 648-653 ◽  
Author(s):  
Oksana S Mikhalchenko ◽  
Dina V Korchagina ◽  
Konstantin P Volcho ◽  
Nariman F Salakhutdinov

Conditions enabling the single-step preparative synthesis of chiral 4-fluoropolyhydro-2H-chromenes in good yields through a reaction between monoterpenoid alcohols with para-menthane skeleton and aldehydes were developed for the first time. The BF3·Et2O/H2O system is used both as a catalyst and as a fluorine source. The reaction can involve aliphatic aldehydes as well as aromatic aldehydes containing various acceptor and donor substituents. 4-Hydroxyhexahydro-2H-chromenes were demonstrated to be capable of converting to 4-fluorohexahydro-2H-chromenes under the developed conditions, the reaction occurs with inversion of configuration.


2004 ◽  
Vol 50 (11) ◽  
pp. 125-133 ◽  
Author(s):  
G. Sin ◽  
P.A. Vanrolleghem

An improved methodology based on a nitrate biosensor is developed and applied successfully for in-depth monitoring and study of anoxic activated sludge activities. The major advantages of the methodology are its simplicity, reliability and high data quality. The resulting data allowed for the first time to monitor anoxic respiration rate of activated sludge (nitrate uptake rate (NUR)) at a high time resolution making it clearly comparable with high frequency oxygen uptake rate (OUR) measurements obtained under aerobic conditions. Further, the anoxic respiration data resulting from a pulse addition of carbon source to endogenously respiring anoxic activated sludge shows a clear start-up phenomenon and storage tail that is usually also observed in high-frequency OUR measurements. Finally, the improved methodology can be expected to serve as an anoxic respirometer for activated sludge treatment plants where denitrification process occurs in single-step. Further, it can be used for a variety of purposes e.g. for toxicity and activity monitoring, process control and parameter estimation of the activated sludge process, similar to the aerobic respirometers.


Synthesis ◽  
2020 ◽  
Vol 52 (16) ◽  
pp. 2395-2409
Author(s):  
Weiwei Qin ◽  
Zhaodong Li ◽  
Yiming Du ◽  
Yue Chen ◽  
Yun-Lin Liu

An efficient, PhI(OAc)2-mediated, radical azidoheteroarylation of alkenes under transition-metal-free conditions is reported by employing TMSN3 and quinoxalin-2(1H)-ones as coupling partners. This domino reaction allows an efficient synthesis of valuable orangoazides containing quinoxalin-2(1H)-one derivatives and could be extended to phosphinyl-alkylated quinoxalin-2(1H)-one in a single step in moderate to excellent yields under mild conditions, as demonstrated by the preliminary antibacterial evaluation against Magnaporthe grisea for the first time. Mechanistic studies revealed that this transformation undergoes a cascade addition pathway controlled by a polar radical.


Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 997
Author(s):  
Nicolas Vogt ◽  
Vasily Sivchik ◽  
Aaron Sandleben ◽  
Gerald Hörner ◽  
Axel Klein

The organonickel complexes [Ni(Phbpy)X] (X = Br, OAc, CN) were obtained for the first time in a direct base-assisted arene C(sp2)–H cyclometalation reaction from the rather unreactive precursor materials NiX2 and HPhbpy (6-phenyl-2,2′-bipyridine) or from the versatile precursor [Ni(HPhbpy)Br2]2. Different from previously necessary C‒Br oxidative addition at Ni(0), an extended scan of reaction conditions allowed quantitative access to the title compound from Ni(II) on synthetically useful timescales through base-assisted C‒H activation in nonpolar media at elevated temperature. Optimisation of the reaction conditions (various bases, solvents, methods) identified 1:2 mixtures of acetate and carbonate as unrivalled synergetic base pairs in the optimum protocol that holds promise as a readily usable and easily tuneable access to a wide range of direct nickelation products. While for the base-assisted C‒H metalation of the noble metals Ru, Ir, Rh, or Pd, this acetate/carbonate method has been established for a few years, our study represents the leap into the world of the base metals of the 3d series.


The Analyst ◽  
2014 ◽  
Vol 139 (9) ◽  
pp. 2193-2198 ◽  
Author(s):  
Yun Zhang ◽  
Fang Liu ◽  
Jinfang Nie ◽  
Fuyang Jiang ◽  
Caibin Zhou ◽  
...  

This paper describes for the first time an electrochemical biosensor, which employs a DNA probe modified with a redox tag close to electrode surface, for picomolar detection of a sequence-specific DNA-binding protein.


2014 ◽  
Vol 50 (71) ◽  
pp. 10210-10213 ◽  
Author(s):  
Alexandr V. Vinogradov ◽  
Haldor Zaake-Hertling ◽  
Evamarie Hey-Hawkins ◽  
Alexandr V. Agafonov ◽  
G. A. Seisenbaeva ◽  
...  

A single-step hydrothermal synthesis of a TiO2–Mil-125 composite was applied for the first time to produce a depleted perovskite/TiO2–MOF heterojunction solar cell with 6.4% power conversion efficiency.


2020 ◽  
Vol 9 (3) ◽  
pp. 1389-1394

The one-step synthesis of high-quality graphene derivatives via CVD process has gained considerable importance nowadays for high-performance electronics and sensors. However, the use of harsh chemicals, high temperature, sensitivity, and the problem of separation of graphene from the substrate, motivated the one-step synthesis of graphene from a non-graphitic precursor, bypassing the use of graphite. In this paper, we have reported for the first time, the synthesis of graphene nanosheets from sugarcane bagasse at the normal atmospheric condition in a single step, avoiding the formation of GO. Here, the pyrolysis of sugarcane bagasse was carried out in the temperature range of 250-450o C in the presence of sodium hydroxide. The results suggested that even the low temperature (250–450o C) facilitated the development of graphitic planes via condensation and aromatization of the glucose monomers present in the precursor. The XRD pattern showed 2θ at around 25o in each case, which confirmed the formation of graphene instead of GO. The FESEM, TEM, and EDX analysis proved the formation of few-layer nanosheets of graphene from carbon-rich waste precursors in a single step.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8132 ◽  
Author(s):  
Junfang Hao ◽  
Fangyu Wang ◽  
Guangxu Xing ◽  
Yunchao Liu ◽  
Ruiguang Deng ◽  
...  

Background Affinity peptides, as a core part of affinity chromatography, play an important role in the purification of target molecules. Methods Here we describe the use of molecular docking technology for virtual screening of affinity peptides that specifically recognize the PCV2 Cap protein for the first time. Thirteen candidate peptides with high scores were obtained and then further characterized. Experimentally, the affinity and sensitivity of the peptides studied were identified by ELISA and LSPR, respectively. In order to investigate the purification effect of a selected peptide (L11) for the recombinant PCV2 Cap protein, it was coupled to NHS agarose magnetic beads as an affinity adsorbent (NaMB-L11); and the ligand density of the affinity adsorbent and pH value in the purification of the recombinant PCV2 Cap protein were optimized. Results Our data showed that the peptide L11- DYWWQSWE has the smallest KD = 103 nM with higher specificity for PCV2 Cap protein recognition. The NaMB-L11 affinity adsorbent yielded a purified Cap sample with 98% purity at 90% recovery in a single step. Conclusion Based on the structure, we obtained a high affinity peptide L11 binding to the PCV2 Cap protein by molecular docking technology. It not only provides a theoretical basis for the design of PCV2 Cap affinity peptide, but a new method for the purification of the PCV2 Cap protein.


2022 ◽  
Author(s):  
Stephen Ting ◽  
Wendy Williams ◽  
Abigail Doyle

The oxidative addition of aryl halides to bipyridine- or phenanthroline-ligated nickel(I) is a commonly proposed step in nickel catalysis. However, there is a scarcity of complexes of this type that both are well-defined and undergo oxidative addition with aryl halides, hampering organometallic studies of this process. We report the synthesis of a well-defined Ni(I) complex, [(CO2Etbpy)NiCl]4 (1). Its solution-phase speciation is characterized by a significant population of monomer and a redox equilibrium that can be perturbed by π-acceptors and σ-donors. 1 reacts readily with aryl bromides, and mechanistic studies are consistent with a mechanism proceeding through an initial Ni(I) → Ni(III) oxidative addition. Such a process was demonstrated stoichiometrically for the first time, affording a structurally characterized Ni(III) aryl complex.


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