Recent progress in the direct synthesis of γ-valerolactone from biomass-derived sugars catalyzed by RANEY® Ni–Sn alloy supported on aluminium hydroxide

2020 ◽  
Vol 10 (22) ◽  
pp. 7768-7778
Author(s):  
Rodiansono ◽  
Maria Dewi Astuti ◽  
Kamilia Mustikasari ◽  
Sadang Husain ◽  
Sutomo

Direct synthesis of γ-valerolactone from sugars using RANEY® nickel–tin alloy supported on aluminum hydroxide catalysts under mild reaction conditions produced an outstanding yield up to 74.9%.

2021 ◽  
Vol 33 (10) ◽  
pp. 2411-2416
Author(s):  
M. Vennila ◽  
G. Jayapriya ◽  
T. Maheswari

Aluminum hydroxide nanoparticles were synthesized using sodium aluminate (NaAlO2) solution and varying amounts of ethanol and methanol under different reaction conditions. The synthesized nanoparticles were characterized using XRD, FESEM and FTIR techniques. The synthesized aluminium hydroxide nanoparticles employed as a catalyst to generate hydrogen from Al/H2O reaction medium. The maximum hydrogen generation with 100% efficiency achieved within 1.50 h at 1:1:200 ratio of Al:Al(OH)3:H2O. This mode of hydrogen generation was collective, non-hazardous, non-corrosive and very promising alternate fuel for energy system.


2020 ◽  
Vol 17 ◽  
Author(s):  
Mohsen A.-M. Gomaa ◽  
Huda A. Ali

Background : The reactivity of 4-(dicyanomethylene)-3-methyl-l-phenyl-2-pyrazoline-5-one DCNP 1 and its derivatives makes it valuable as a building block for the synthesis of heterocyclic compounds like pyrazolo-imidazoles, - thiazoles, spiropyridines, spiropyrroles, spiropyrans and others. As a number of publications have reported on the reactivity of DCNP and its derivatives, we compiled some features of this interesting molecule. Objective: This article aims to review the preparation of DCNP, its reactivity and application in heterocyclic and dyes synthesis. Conclusion: In this review we have provided an overview of recent progress in the chemistry of DCNP and its significance in synthesis of various classes of heterocyclic compounds and dyes. The unique reactivity of DCNP offers unprecedentedly mild reaction conditions for the generation of versatile cynomethylene dyes from a wide range of precursors including amines, α-aminocarboxylic acids, their esters, phenols, malononitriles and azacrown ethers. We anticipate that more innovative transformations involving DCNP will continue to emerge in the near future.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4598
Author(s):  
Eva M. Maya ◽  
Antonio Valverde-González ◽  
Marta Iglesias

Commercial iron (II) phthalocyanine (FePc) was knitted with biphenyl using a Friedel–Crafts reaction to yield a micro-meso porous organic polymer (FePc-POP) with a specific surface area of 427 m2/g and 5.42% of iron loading. This strategy allowed for the direct synthesis of a heterogeneous catalyst from an iron containing monomer. The catalytic system, formed by the knitted polymer containing FePc and DMAP (4-dimethylamino pyridine) as base, results in an efficient heterogeneous catalyst in the cycloaddition of CO2 to epichlorohydrin to selectively obtain the corresponding cyclic carbonate. Thus, a TON (mmol substrate converted/mmol catalysts used) value of 2700 was reached in 3 h under mild reaction conditions (solvent free, 90 °C, 3 bar of CO2). The catalyst does not exhibit leaching during the reactions, which was attributed to the excellent stability of the metal in the macrocycle.


Synthesis ◽  
2020 ◽  
Author(s):  
Yasuyuki Ura

AbstractCatalytic anti-Markovnikov (AM) oxidation of terminal alkenes can provide terminally oxyfunctionalized organic compounds. This short review mainly summarizes our recent progress on the Pd-catalyzed AM oxidations of aromatic and aliphatic terminal alkenes to give terminal acetals (oxidative acetalization) and aldehydes (Wacker-type oxidation), along with related reports. These reactions demonstrate the efficacy of the PdCl2(MeCN)2/CuCl/electron-deficient cyclic alkenes/O2 catalytic system. Notably, electron-deficient cyclic alkenes such as p-benzoquinones (BQs) and maleimides are key additives that facilitate nucleophilic attack of oxygen nucleophiles on coordinated terminal alkenes and enhance the AM selectivity. BQs also function to oxidize Pd(0) depending on the reaction conditions. Several other factors that improve the AM selectivity, such as the steric demand of the nucleo­philes, slow substrate addition, and halogen-directing groups, are also discussed.1 Introduction2 Anti-Markovnikov Oxidation of Aromatic Alkenes to Terminal Acetals­3 Anti-Markovnikov Oxidation of Aromatic Alkenes to Aldehydes4 Anti-Markovnikov Oxidation of Aliphatic Alkenes to Terminal Acetals­5 Anti-Markovnikov Oxidation of Aliphatic Alkenes to Aldehydes6 Conclusion


2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.


2005 ◽  
Vol 83 (6-7) ◽  
pp. 937-942 ◽  
Author(s):  
Masaharu Sugiura ◽  
Chieko Mori ◽  
Keiichi Hirano ◽  
Shū Kobayashi

Hydroxyglycine, the ammonia adduct of glyoxylic acid, was found to react with various allylboronates in the presence of triethylamine in methanol to give unprotected α-amino acids directly with high stereoselectivity. For instance, the reactions with (E)- and (Z)-crotylboronates afforded the corresponding anti- and syn-crotylated products (isoleucine and alloisoleucine after hydrogenation) with high diastereoselectivity, respectively. Interestingly, it was found that isomerization of the products (γ-adducts to α-adducts) occurred under the reaction conditions in some cases. Control experiments have suggested that the isomerization took place via 2-aza (or azonia) Cope rearrangement of imines derived from γ-adducts and glyoxylic acid.Key words: hydroxyglycine, glyoxylic acid, allylboronates, α-amino acids, allylglycines, isoleucine, alloisoleucine, stereoselective reactions, isomerization, 2-aza (azonia) Cope rearrangement.


Synlett ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 2525-2538 ◽  
Author(s):  
James Bull ◽  
Renzo Luisi ◽  
Leonardo Degennaro

Sulfoximines are emerging as valuable new isosteres for use in medicinal chemistry, with the potential to modulate physicochemical properties. Recent developments in synthetic strategies have made the unprotected ‘free’ NH-sulfoximine group more readily available, facilitating further study. This account reviews approaches to NH-sulfoximines, with a focus on our contribution to the field. Starting from the development of catalytic strategies involving transition metals, more sustainable metal-free processes have been discovered. In particular, the use of hypervalent iodine reagents to mediate NH-transfer to sulfoxides is described, along with an assessment of the substrate scope. Furthermore, a one-pot strategy to convert sulfides directly into NH-sulfoximines is discussed, with N- and O-transfer occurring under the reaction conditions. Mechanistic evidence for the new procedures is included as well as relevant synthetic applications that further exemplify the potential of these approaches.1 Introduction2 Strategies to Form NH-Sulfoximines Involving Transition-Metal Catalysts3 Metal-Free Strategies to Prepare NH-Sulfoximines4 Mechanistic Evidence for the Direct Synthesis of NH-Sulfoximines from Sulfoxides and Sulfides5 Further Applications6 Conclusion


2015 ◽  
Vol 2 (4) ◽  
pp. 403-415 ◽  
Author(s):  
Yujie Liang ◽  
Yu-Feng Liang ◽  
Ning Jiao

This tutorial account summarizes the recent progress in Cu- or Fe-catalyzed C–H/C–C bond nitrogenation reactions for the direct synthesis of N-containing compounds.


ACS Catalysis ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 6445-6452 ◽  
Author(s):  
Vitaly V. Ordomsky ◽  
Yuan Luo ◽  
Bang Gu ◽  
Alexandre Carvalho ◽  
Petr A. Chernavskii ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document