CIBA Geigy asymmetric ketone reduction process

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.

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Scalable Synthesis of Functionalized Ferrocenyl Azides and Amines Enabled by Flow Chemistry

10.26434/chemrxiv.11321975 ◽

2019 ◽

Author(s):

Merlin Kleoff ◽

Johannes Schwan ◽

Lisa Boeser ◽

Bence Hartmayer ◽

Mathias Christmann ◽

...

Keyword(s):

Reaction Time ◽

Heterogeneous Reaction ◽

Reduction Process ◽

Flow Chemistry ◽

Subsequent Reaction ◽

Scalable Synthesis ◽

High Yields ◽

Reactor Section

A scalable access to functionalized 1,1’- and 1,2-ferrocenyl azides has been realized in flow. By halogen‒lithium exchange of ferrocenyl halides and subsequent reaction with tosyl azide, a variety of functionalized ferrocenyl azides was obtained in high yields. To allow a scalable preparation of these potentially explosive compounds, an efficient flow protocol was developed accelerating the reaction time to minutes and circumventing accumulation of potentially hazardous intermediates. Switching from homogeneous to triphasic flow amidst process was key for handling a heterogeneous reaction mixture formed after a heated reactor section. The corresponding and synthetically versatile ferrocenyl amines were then prepared by a reliable reduction process.

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Convergent Total Synthesis of Principinol D, a Rearranged Kaurane Diterpenoid

10.26434/chemrxiv.7865168.v4 ◽

2019 ◽

Author(s):

Timothy Newhouse ◽

Aneta Turlik ◽

Yifeng Chen ◽

Anthony Scruse

Keyword(s):

Total Synthesis ◽

Natural Product ◽

Late Stage ◽

Membered Ring ◽

Entry Point ◽

Ketone Reduction ◽

Coupling Approach

<div> <p>The total synthesis of principinol D, a rearranged kaurane diterpenoid, is reported. This grayanane natural product is constructed via a convergent fragment coupling approach, wherein the central 7-membered ring is synthesized at a late stage. The bicyclo[3.2.1]octane fragment is accessed by a Ni-catalyzed α-vinylation reaction. Strategic reductions include a diastereoselective SmI<sub>2</sub>-mediated ketone reduction with PhSH and a new protocol for selective ester reduction in the presence of ketones. The convergent strategy reported herein may be an entry point to the larger class of kaurane diterpenoids.</p> </div>

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Green synthesis of iron nanoparticles using flower extract of Piliostigma thonningii and their antibacterial activity evaluation

10.31221/osf.io/57zrj ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Antibacterial Activity ◽

Environmental Remediation ◽

Iron Nanoparticles ◽

Reduction Process ◽

Xrd Analysis ◽

Visible Range ◽

Magnetic Storage ◽

Ferrous Chloride ◽

Flower Extract ◽

Piliostigma Thonningii

Iron nanoparticles have gained tremendous attention due to their application in magnetic storage media, ferrofluids, biosensors, catalysts, separation processes, environmental remediation and antibacterial activity. In the present paper, iron nanoparticles were synthesized using aqueous flower extract of Piliostigma thonningii, a natural nontoxic herbal infusion. Iron nanoparticles were generated by reaction of ferrous chloride solution with the flower extract. The reductants present in the flower extract acted as reducing and stabilizing agents. UV-vis analysis of the iron nanoparticles showed continuous absorption in the visible range suggesting the iron nanoparticles were amorphous. This was confirmed by X-ray diffraction (XRD) analysis which did not have distinct diffraction peaks. Scanning electron microscopy (SEM) analysis revealed that the synthesized iron nanoparticles were aggregated as irregular clusters with rough surfaces. FT-IR studies showed the functional groups that participated in the bio-reduction process to include a C-H stretch (due to alkane CH3, CH2 or CH), C=O stretch (due to aldehydes), O-H bend (due to tert-alcohol or phenol), C-O stretch (due to aldehydes or phenols) and C-O stretch (due to alcohols) corresponding to absorptions at 2929.00, 1721.53, 1405.19, 1266.31 and 1030.02 cm-1 respectively. The iron nanoparticles showed significant antibacterial activity against Escharichia coli and Staphylococcus aureus suggesting potential antibacterial application.

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Preparation of primary Al-Si alloy from bauxite tailings by carbothermal reduction process

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(09)60112-6 ◽

2010 ◽

Vol 20 (1) ◽

pp. 147-152 ◽

Cited By ~ 13

Author(s):

Dong YANG ◽

Nai-xiang FENG ◽

Yao-wu WANG ◽

Xiao-lei WU

Keyword(s):

Carbothermal Reduction ◽

Reduction Process ◽

Bauxite Tailings

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Effect of synthesis and activation methods on the character of CoMo/ultrastable Y-zeolite catalysts

Open Chemistry ◽

10.1515/chem-2021-0064 ◽

2021 ◽

Vol 19 (1) ◽

pp. 745-754

Author(s):

Khoirina Dwi Nugrahaningtyas ◽

Eddy Heraldy ◽

Rachmadani ◽

Yuniawan Hidayat ◽

Indriana Kartini

Keyword(s):

Electron Microscopy ◽

Reduction Process ◽

Particle Morphology ◽

Zeolite Catalysts ◽

X Ray Diffraction ◽

Y Zeolite ◽

X Ray ◽

Irregular Particle ◽

Transmission Electron ◽

Pure Metals

Abstract The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.

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