An efficient protocol for the synthesis of a variety of <a href="https://www.sciencedirect.com/topics/chemical-engineering/azobenzene">azobenzenes</a> and <a href="https://www.sciencedirect.com/topics/chemical-engineering/hydrazine">hydrazines</a> from aromatic <a href="https://www.sciencedirect.com/topics/chemical-engineering/amine">amines</a> under mild reaction conditions is developed using Cu(I) catalyst. The copper cataylst used in this study comprises of CuBr, DMAP and AIBN. The plausible proposed mechanism for this dehydrogenative homo coupling of aromatic amines is depicted.

Rajasekhara Reddy Sabbasani

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Reddy C.B.R

Naidu S.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Catalysis Communications

A symmetrical azo-based Luminol derivative 2 was synthesized using catalytic dehydrogenative coupling reaction procedure. This symmetrical molecule shows blue fluorescence in polar aprotic solvents (λmax = 450 nm). With an increase in aqueous content 2 was exhibiting aggregation caused fluorescence quenching (ACQ) with a red shift of 30 nm (λmax = 480 nm). Distinct emission features were observed for this molecule&nbsp; with a variation in the pH range. In basic medium, deprotonated form of 2 shows fluorescence quenching followed by enhancement of&nbsp; green chemiluminescence (λmax = 490 nm) with H2O2/Fe3+catalytic system. The fluorescence and chemiluminescent (CL) properties of 2 were compared with its parent luminol 1, The &nbsp;CL emission intensity of 2 was found to be about 16 times higher than that of 1. In addition, HOMO-LUMO energy gap for 2 was also calculated using density functional theory (DFT) studies.

Fulltext

Oriental Journal of Chemistry

Green Chemiluminescence of Highly Fluorescent Symmetrical Azo-Based Luminol Derivative

A simple and efficient cascade synthesis was achieved to produce chloro substituted 9-phenyl-6H-benzo[c]chromenes under mild and additive-free reaction conditions via chlorination followed by benzannulation. This would be a green alternative approach to introduce a chlorine atom on poly hetero aromatic rings without use of other toxic and malodorous chlorinating agents. The core structure is a part of several biological active compounds, and this new protocol allows design of new polyheterocyclic frameworks using an alternative to traditional cross-coupling strategies.

Bulletin of the Chemical Society of Japan

Regioselective Cascade Synthesis of Chloro-Substituted 6H-Benzo[c]chromenes via Benzannulation

A mild and efficient, ionic-liquid-assisted green protocol for the chemoselective oxygenation of benzylic C-H bonds to corresponding ketones using ionic liquid [bmim]Br with tert-butyl hydroperoxide has been developed. The method reported in this paper has the advantages of [bmim]Br acting as recyclable solvent and reagent. The usage of additives such as acids or bases and metal salts is not required. The developed strategy is further extended to oxidation of secondary alcohols to respective ketones under similar optimized reaction conditions.

Journal of Molecular Liquids

Ionic liquid [bmim]Br assisted chemoselective benzylic C H oxidations using -butyl hydroperoxide

Catalytic oxidation reactions often suffer from drawbacks such as low yields and poor selectivity. Particularly, selective oxidation of alcohols becomes more difficult when a compound contains more than one oxidizable functional group. In order to deliver a methodology that addresses these issues, herein we report an efficient, aerobic, chemoselective and simplified approach to oxidize a broad range of benzyl and propargyl alcohols containing diverse functional groups to their corresponding aldehydes and ketones in excellent yields under mild reaction conditions. Optimal yields were obtained at room temperature using 1 mmol substrate, 10 mol % copper(I) iodide, 10 mol % 4-dimethylaminopyridine (DMAP), and 1 mol % 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) in acetonitrile, under an oxygen balloon. The catalytic system can be applied even when sensitive and oxidizable groups such as alkynes, amines, and phenols are present; starting materials and products containing such groups were found to be stable under the developed conditions.

ChemistryOpen

Chemoselective Oxidation of Benzyl, Amino, and Propargyl Alcohols to Aldehydes and Ketones under Mild Reaction Conditions

Oxidation of propargylic alcohols to the corresponding aldehydes and ketones was achieved at room temperature using 2,2,6,6-tetramethylpiperidine-1- oxyl (TEMPO) and calcium hypochlorite (Ca(OCl)2). Propargylic diols yielded corresponding dialdehydes as the product. This system was found to be very efficient for both the electron donating and electron withdrawing groups such as methoxy and nitro substituted alcohols, respectively. This method does not require any additives and demonstrates the controlled, selective oxidation of propargylic alcohols affording up to 97% isolated yield. © The Royal Society of Chemistry 2013.

Journal	Data powered by TypesetCatalysis Communications
Publisher	Data powered by TypesetElsevier BV
ISSN	1566-7367
Open Access	0