A Green Method for the Electroorganic Synthesis of New 1,3-Indandione Derivatives

Abstract

On the other hand, it has been reported that ortho-and para-hydroquinones and their quinone derivatives are abundant in nature and play important roles in many biological systems. [7][8][9][10][11] In addition, many chemicals of this category demonstrate an antioxidant activity and are able to prevent auto-oxidation via the radical formation inhibition.12) These compounds exhibit a wide variety of physiological and pharmacological properties.13) They participate in normal cell functions such as neurotransmitters. Furthermore, natural pyrocatechols extracted from plants (catechins and other polyphenols from green tea) have been found to illustrate anticancer properties. 14)For these reasons, knowledge of the redox properties of these compounds is important for a better understanding of their behavior in biological environments. Redox properties of some derivatives of these compounds in aqueous solutions is documented. [15][16][17][18][19][20][21][22] We thought that synthesis of a new 1,3-indandione derivatives with both structures of 1,3-indandione and hydroquinone would be useful from the point of view of pharmaceutical properties. This idea prompted us to development of a facile and environmentally friendly reagentless electrochemical method for the synthesis of some new 1,3-indandione derivatives in aqueous solutions with high atomic economy under ambient conditions and in an undivided cell using a graphite electrode and delineates the application of electrochemical studies in the design of an electrochemical method for the synthesis of new 1,3-indandione derivatives (5a-c).Electroorganic Reactions of 4-tert-Butylcatechol (1a) and 4-Methylcatechol (1b) Figure 1, CV a displays the typical successive cyclic voltammogram (CV) of 0.25 mM 4-tert-butylcatechol (1a) in aqueous media (H 2 O : AN, 90 : 10), containing phosphate buffer (pHϭ7.0, cϭ0.15 M). This figure demonstrates one anodic peak (A 1 ) (at 0.291 V) and one corresponding cathodic peak (C 1 ) (at 0.105 V), which corresponds to the transformation of 4-tert-butylcatechol (1a) to o-quinone-4-tert-butyl (2a) and vice versa within a quasireversible two-electron and two-proton process (DEpϭ 0.186 V). 23,24) A peak current ratio (I P A1 /I P C1 ) of nearly unity, particularly during the repetitive potential recycle, can be considered as a criterion for the stability of o-quinone produced on the electrode surface under the experimental conditions. In other words, any hydroxylation 25,26) or dimerization 27,28) reactions are too slow to be observed on the time scale of the cyclic voltammetry.The oxidation of 4-tert-butylcatechol (1a) in the presence of 2-phenyl-1,3-indandione (3) (pK a ϭ4.1) 29) as a nucleophile was studied in detail. Figure 1, CV b presents the cyclic voltammogram obtained for a 0.25 mM solution of 1a in the presence of 0.25 mM 3. The corresponding voltammogram exhibits one anodic peak at 0.364 V (A 1 ) vs. the reference electrode, where the cathodic counterpart of the anodic peak A 1 decreases. In this condition, the positive shift of the A 1 p...

Electro-Organic Synthesis and Characterization of New Dihydroxybenzene Dinitrile Derivatives with Fluorescent Properties

“…12) Hydroquinone oxidation in aqueous solutions is well documented. [13][14][15][16][17][18][19][20] It involves a transfer of two electrons and two protons to create the associated quinone. The electrochemical synthesis between catechol, 4-methylcatechol, 1,4-dihydroxybenzene and benzenesulfinic acids was reported by S. M. Golabi and co-workers.…”

Conducting Polymer-based Biohybrid Materials : Towards Microphysiological Chips and Soft Actuators for Bone Tissue Engineering

“…The electrode system can be either a two-electrode system including a WE and a CE/RE to measure the potential across the complete cell, or a three-electrode system including a WE, a CE and a separated RE to measure the potential and current. [173] The WE serving as electron donor or acceptor is the most important since it is where the chemistry of interest occurs. The CE is used to complete the electrical circuit allowing charge flow through the cell.…”

Electrochemical strategies for C–H functionalization and C–N bond formation

“…[675][676][677][678][679][680][681] Considering their relatively low oxidation potentials, it is perhaps unsurprising that an assortment of nucleophiles are compatible with these processes without being subjected to oxidation. Here, amines, [682][683][684][685][686][687][688][689] azide, 690,691 enolates and other carbon nucleophiles, [692][693][694][695][696][697][698][699][700][701][702][703][704][705][706][707][708][709][710][711] nitrate, 712 sulfinates [713][714][715][716][717][718][719][720][721][722][723]…”