Chemical and spectroscopic studies in metal β-diketonates. II. Nitration of metal β-diketonates

1967 ◽  
Vol 20 (4) ◽  
pp. 649 ◽  
Author(s):  
PR Singh ◽  
R Sahai
Keyword(s):  
Acetic Anhydride ◽  
Electronic Spectra ◽  
Spectroscopic Studies ◽  
Single Step ◽  
Ferric Nitrate ◽  
Reaction Conditions ◽  
Step Process ◽  
Metal Nitrates ◽  
First Time ◽  
Cobaltous Nitrate

Bis(3-nitropentane-2,4-dionato)-beryllium(II), -copper(II), and - palladium(II); tris(3-nitropentane-2,4-dionato)-aluminium(III), - chromium(III), -manganese(III), -iron(III), and -cobalt(III); tetrakis(3-nitropentane-2,4-dionato)zirconium(IV); and tris (3-nitro- 1,3-diphenylpropane-1,3-dionato)-aluminium(III) and -chromium(III) have been prepared by the nitration of the respective metal chelates of acetylacetone and 1,3-diphenylpropane-1,3-dione. Ferric nitrate, cobaltous nitrate, and nickel nitrate have been used as nitrating agents for the first time. The nitro chelates have also been prepared by a direct, single-step process using metal nitrates, acetic anhydride, and the ligands. In several cases, metal replacement reactions have been observed to be taking place in conjunction with nitration under nitration reaction conditions. Infrared, ultraviolet, and visible electronic spectra have been recorded and are discussed.

scholarly journals A Greener Enzymatic Oligoesterification of Biobased Renewable Synthons

2021 ◽  
Author(s):  
Juan Villavicencio ◽  
Ferley Orozco ◽  
Ricardo Benitez ◽  
Jaime Martin ◽  
Giovanni Rojas
Keyword(s):  
Molecular Weight ◽  
Molar Mass ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Step Process ◽  
Gel Permeation ◽  
One Step ◽  
First Time ◽  
Temperature Time

Polyesters of xylitol and succinic acid were prepared yielding from 70 to 75% by enzymecatalyzed esterification using a molar mass from 1:1 to 2:5 at 120 and 140 °C employing from 1 to 10% m/m of enzyme. Control over branching degree was achieved by tuning the reaction conditions (temperature, time, comonomer ratio, enzyme content). This one-step process from renewable starting materials avoids protection-deprotection techniques, as well as the use of toxic solvents by introducing limonene as solvent for polyesterification for the first time. All materials were structurally characterized by infrared (IR) and nuclear magnetic resonance (NMR)spectroscopy, their thermal properties were studied by differential scanning calorimetry (DSC)and thermogravimetric analysis (TGA), and the molecular weight of samples were obtained by gel-permeation chromatography (GPC).

scholarly journals One-Pot Synthesis of Heavier Group 14 N-Heterocyclic Carbene Using Organosilicon Reductant

Inorganics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 69 ◽  
Author(s):  
Ravindra Raut ◽  
Sheikh Amin ◽  
Padmini Sahoo ◽  
Vikas Kumar ◽  
Moumita Majumdar
Keyword(s):  
Alkali Metal ◽  
Reducing Agents ◽  
Single Step ◽  
Reducing Agent ◽  
Metal Salts ◽  
Group 14 ◽  
Reaction Conditions ◽  
One Pot ◽  
Step Process ◽  
One Pot Synthesis

Syntheses of heavier Group 14 analogues of “Arduengo-type” N-heterocyclic carbene majorly involved the use of conventional alkali metal-based reducing agents under harsh reaction conditions. The accompanied reductant-derived metal salts and chances of over-reduced impurities often led to isolation difficulties in this multi-step process. In order to overcome these shortcomings, we have used 1,4-bis-(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene as a milder reducing agent for the preparation of N-heterocyclic germylenes (NHGe) and stannylenes (NHSn). The reaction occurs in a single step with moderate yields from the mixture of N-substituted 1,4-diaza-1,3-butadiene, E(II) (E(II) = GeCl2·dioxane, SnCl2) and the organosilicon reductant. The volatile byproducts trimethylsilyl chloride and pyrazine could be removed readily under vacuum. No significant over reduction was observed in this process. However, N-heterocyclic silylene (NHSi) could not be synthesized using an even stronger organosilicon reductant under thermal and photochemical conditions.

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar
Keyword(s):  
Green Synthesis ◽  
Color Change ◽  
Limit Of Detection ◽  
Aqueous Media ◽  
Suitable Condition ◽  
Cost Effective ◽  
Spectroscopic Studies ◽  
Calibration Plot ◽  
First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

scholarly journals Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon–carbon bonds

2017 ◽  
Vol 15 (10) ◽  
pp. 2163-2167 ◽  
Author(s):  
Zhouting Rong ◽  
Antonio M. Echavarren
Keyword(s):  
Single Step ◽  
Simultaneous Formation ◽  
Broad Scope ◽  
Carbon Carbon Bonds ◽  
Carbon Bonds ◽  
First Time ◽  
High Stereoselectivity

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.

scholarly journals A Sustainable Improvement of ω-Bromoalkylphosphonates Synthesis to Access Novel KuQuinones

Organics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 107-117
Author(s):  
Mattia Forchetta ◽  
Valeria Conte ◽  
Giulia Fiorani ◽  
Pierluca Galloni ◽  
Federica Sabuzi
Keyword(s):  
Metal Oxides ◽  
Phosphonic Acid ◽  
Organic Molecules ◽  
Building Blocks ◽  
Reaction Conditions ◽  
Phosphonic Acids ◽  
Sustainable Improvement ◽  
Phosphonate Esters ◽  
First Time ◽  
Complex Organic

Owing to the attractiveness of organic phosphonic acids and esters in the pharmacological field and in the functionalization of conductive metal-oxides, the research of effective synthetic protocols is pivotal. Among the others, ω-bromoalkylphosphonates are gaining particular attention because they are useful building blocks for the tailored functionalization of complex organic molecules. Hence, in this work, the optimization of Michaelis–Arbuzov reaction conditions for ω-bromoalkylphosphonates has been performed, to improve process sustainability while maintaining good yields. Synthesized ω-bromoalkylphosphonates have been successfully adopted for the synthesis of new KuQuinone phosphonate esters and, by hydrolysis, phosphonic acid KuQuinone derivatives have been obtained for the first time. Considering the high affinity with metal-oxides, KuQuinones bearing phosphonic acid terminal groups are promising candidates for biomedical and photo(electro)chemical applications.

Sulfonyl Radical Triggered Selective Iodosulfonylation and Bicycli-zations of 1,6-Dienes

2021 ◽  
Author(s):  
Shi-Ping Wu ◽  
Dong-Kai Wang ◽  
Qing-Qing Kang ◽  
Guo-Ping Ge ◽  
Hongxing Zheng ◽  
...  
Keyword(s):  
Functional Group ◽  
High Selectivity ◽  
Reaction Conditions ◽  
First Time

A novel sulfonyl radical triggered selective iodosulfonylation and bicyclizations of 1,6-dienes has been described for the first time. High selectivity and efficiency, mild reaction conditions, excellent functional group compatibility, and...

Medium-sized cyclophanes, part 59:1 Nitration of [3.3]- and [3.3.3]metacyclophanes — Through-space electronic interactions between two or three benzene rings

2002 ◽  
Vol 80 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Takehiko Yamato ◽  
Koji Tsuchihashi ◽  
Noriko Nakamura ◽  
Mai Hirahara ◽  
Hirohisa Tsuzuki
Keyword(s):  
Acetic Anhydride ◽  
Electronic Interaction ◽  
Reaction Conditions ◽  
Tert Butyl ◽  
Mixed Acid ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Starting Compound ◽  
Nitration Product ◽  
Fuming Nitric Acid

The two tert-butyl groups of anti-6,15-di-tert-butyl-9,18-dimethoxy[3.3]metacyclophane (anti-4) are both ipso-nitrated even under mild reaction conditions such as copper(II) nitrate in an acetic anhydride solution because of the decreased deactivation of the second aromatic ring by the introduced nitro group. On the other hand, anti-5,13-di-tert-butyl-8,16-dimethoxy[2.2]metacyclophane (anti-1) undergoes replacement of only one tert-butyl group under the same reaction conditions. The higher yields of the twofold ipso-nitration product anti-7 were obtained in nitration of anti-4 with fuming nitric acid or mixed acid (HNO3–H2SO4). Thus, the number of ipso-nitrations at the tert-butyl groups of anti-4 was strongly affected by the reactivity of the nitration reagent. Nitration of the corresponding syn-conformer syn-4 with copper(II) nitrate in an acetic anhydride solution, however, led only to the recovery of the starting compound. The presently developed procedure was further applied to the direct removal of the tert-butyl group by electrophilic substitution of the larger-sized ring macrocyclic metacyclophanes, cone- and partial-cone-tri-tert-butyl[3.3.3]metacyclophanes 11.Key words: [3n]metacyclophanes, conformation, ipso-nitration, through-space electronic interaction, crystal structure.

scholarly journals A practical way to synthesize chiral fluoro-containing polyhydro-2H-chromenes from monoterpenoids

2016 ◽  
Vol 12 ◽  
pp. 648-653 ◽  
Author(s):  
Oksana S Mikhalchenko ◽  
Dina V Korchagina ◽  
Konstantin P Volcho ◽  
Nariman F Salakhutdinov
Keyword(s):  
Aromatic Aldehydes ◽  
Single Step ◽  
Preparative Synthesis ◽  
Aliphatic Aldehydes ◽  
First Time

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.

scholarly journals New opportunities in the stereoselective dearomatization of indoles

2016 ◽  
Vol 88 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Elisabetta Manoni ◽  
Assunta De Nisi ◽  
Marco Bandini
Keyword(s):  
Acid Catalysis ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Reaction Conditions ◽  
Brönsted Acid ◽  
High Yields ◽  
First Time ◽  
Tailored Design ◽  
Bronsted Acid Catalysis

AbstractThe regio- and stereoselective dearomatization of indoles is realized for the first time by combining readily available indolyl precursors and electron-rich allenes, namely allenamides and aryloxyallenes. Inter- as well as intramolecular condensations were realized under gold and Brønsted acid catalysis providing a range of densely functionalized indoline and indolenine cores in high yields and excellent stereochemical outcome. Chemodivergent reaction profiles (Micheal-type addition vs. [2+2]-cycloaddition) were realized by a tailored design of both reaction conditions and functionalization of the reaction partners.

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