Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives

Hamid Reza Shaterian; Farzaneh Moradi; Majid Mohammadnia

doi:10.1016/j.crci.2012.09.012

Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives

Hamid Reza Shaterian ¹ ; Farzaneh Moradi ¹ ; Majid Mohammadnia ¹

¹ Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, PO Box 98135-674, Zahedan, Iran

Comptes Rendus. Chimie, Volume 15 (2012) no. 11-12, pp. 1055-1059.

Résumé

An efficient one-pot quantitative procedure for the preparation of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives from four-component reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, aldehydes, and malononitrile in the presence of nano CuO as the catalyst has been developed. The copper(II) oxide nanoparticles can be recovered and reused several times without loss of its activity.

Métadonnées

Reçu le : 2012-05-11
Accepté le : 2012-09-25
Publié le : 2012-11-01

DOI : 10.1016/j.crci.2012.09.012

Mots-clés : 2-Hydroxynaphthalene-1, 4-dione, O-phenylenediamine, Aldehydes, Malononitrile, Nano CuO, Catalyst

Affiliations des auteurs :

Hamid Reza Shaterian ¹ ; Farzaneh Moradi ¹ ; Majid Mohammadnia ¹

¹ Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, PO Box 98135-674, Zahedan, Iran

@article{CRCHIM_2012__15_11-12_1055_0,
     author = {Hamid Reza Shaterian and Farzaneh Moradi and Majid Mohammadnia},
     title = {Nano {copper(II)} oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives},
     journal = {Comptes Rendus. Chimie},
     pages = {1055--1059},
     publisher = {Elsevier},
     volume = {15},
     number = {11-12},
     year = {2012},
     doi = {10.1016/j.crci.2012.09.012},
     language = {en},
}

TY  - JOUR
AU  - Hamid Reza Shaterian
AU  - Farzaneh Moradi
AU  - Majid Mohammadnia
TI  - Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives
JO  - Comptes Rendus. Chimie
PY  - 2012
SP  - 1055
EP  - 1059
VL  - 15
IS  - 11-12
PB  - Elsevier
DO  - 10.1016/j.crci.2012.09.012
LA  - en
ID  - CRCHIM_2012__15_11-12_1055_0
ER  -

%0 Journal Article
%A Hamid Reza Shaterian
%A Farzaneh Moradi
%A Majid Mohammadnia
%T Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives
%J Comptes Rendus. Chimie
%D 2012
%P 1055-1059
%V 15
%N 11-12
%I Elsevier
%R 10.1016/j.crci.2012.09.012
%G en
%F CRCHIM_2012__15_11-12_1055_0

Hamid Reza Shaterian; Farzaneh Moradi; Majid Mohammadnia. Nano copper(II) oxide catalyzed four-component synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives. Comptes Rendus. Chimie, Volume 15 (2012) no. 11-12, pp. 1055-1059. doi : 10.1016/j.crci.2012.09.012. https://comptes-rendus.academie-sciences.fr/chimie/articles/10.1016/j.crci.2012.09.012/

Version originale du texte intégral

Le texte intégral ci-dessous peut contenir quelques erreurs de conversion par rapport à la version officielle de l'article publié.

1 Introduction

Nanomaterials have attracted a great deal of attention in organic synthesis owing to their high surface-to-volume ratio, which are responsible for the higher catalytic activity [1].

The catalytic activity of nano CuO and its green chemistry exhibits good reusability, simple workup procedure and a straightforward approach to use in organic synthesis [2–4].

Phenazines are present in natural and synthetic products showing a variety of biological functions, including antimalarial, trypanocidal, fungicidal, antitumor, and antiplatelet activities [5–9]. Chromenes have been showed remarkable effects as pharmaceuticals [10,11], including antifungal [12,13] and antimicrobial activities [14]. Molecules with phenazines [15] and chromenes [16] moieties have attracted great attention in drug discovery.

The designs of multi-component reactions (MCRs) for the synthesis of diverse groups of compounds, especially the ones that are biologically active, have commanded great attention in green organic synthesis [17–19]. In continuation of our research on multi-component reactions [20–22], herein we wish to describe the preparation of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives with phenazines and chromenes moieties from a four-component reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, aldehydes, and malononitrile in the presence of nano copper(II) oxide as the catalyst under thermal solvent-free conditions (Scheme 1).

Scheme 1
Synthesis of 3-amino-2-cyano-1-aryl-1H-benzo[a]pyrano[2,3-c]phenazines derivatives.

2 Results and discussion

First, to find optimization conditions, the one-pot four-component reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, 4-chlorobenzaldehyde and malononitrile in the presence of the nano copper(II) oxide as catalyst was selected as model. 2-Hydroxynaphthalene-1,4-dione (1 mmol) and o-phenylenediamine (1 mmol) were mixed at 75 °C until a orange solid of benzo[a]phenazine was formed (< 5 min) without using any catalyst under solvent-free conditions. Then, 4-chlorobenzaldehyde (1 mmol), malononitrile (1 mmol), and nano copper(II) oxide as catalyst was added and stirred under thermal conditions. The reaction was carried out with different amount of nano copper(II) oxide as catalyst (5, 10, 15, 25 mol%) at various temperatures (25, 50, 75 °C) (Table 1). As it was shown from Table 1, 10 mol% of nano copper(II) oxide as catalyst at 75 °C afforded 3-amino-2-cyano-1-(4-chlorophenyl)-1H-benzo[a]pyrano[2,3-c]phenazine in 7 min with 94% of yield.

Entry	Catalyst (mol%)	Temperature ( °C)	Time (min)	Yield (%)^a
1	25	25	30	Trace
2	15	50	30	35
3	25	50	28	50
4	5	75	12	83
5	10	75	7	94
6	15	75	7	95

^a Yields refer to isolated pure product.

Next, four-component condensation reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, aromatic aldehydes, and malononitrile under solvent-free conditions for preparation of 3-amino-2-cyano-1-aryl-1H-benzo[a]pyrano[2,3-c]phenazines was investigated (Table 2). The wide ranges of substituted and structurally diverse aldehydes afforded the corresponding products in high to excellent yields using the nano copper(II) oxide as catalyst (Table 2). Aliphatic aldehyde such as heptanal was intact in this reaction (Table 2, Entry 13).

Entry	Aldehydes	Time (min)	Yield (%)^a	Melting Point m.p. ( °C)/Lit. m.p. ( °C) [Ref]
1	Ph	8	92	301–302/(298–300) [23]
2	4-NO₂C₆H₄	8	90	282–283/(281–283) [23]
3	4-FC₆H₄	7	93	276–277/(274–276) [23]
4	4-BrC₆H₄	7	91	285–286/(283–285) [23]
5	4-ClC₆H₄	7	94	290–291/(288–291) [23]
6	3-NO₂C₆H₄	8	89	280/(278–279) [23]
7	4-OH-3-CH₃OC₆H₃	7	89	248–249/(247–248) [23]
8	4-OH-3-NO₂C₆H₃	8	90	292/(290–291) [23]
9	3,4,5-(CH₃O)₃C₆H₂	7	91	253–254/(252–254) [23]
10	4-CH₃C₆H₄	7	90	293–295/(293–294) [23]
11	2-CH₃OC₆H₄	7	90	273/(270–272) [23]
12	2,3-(CH₃O)₂C₆H₃	8	91	295/(292–294) [23]
13	n-Heptanal	24 h	–	–

^a Yields refer to the isolated pure products. The desired known pure products were characterized by comparison of their physical data (melting points, IR, ¹H and ¹³C NMR) with those of known compounds [23]. The same products are made in the presence of acetic acid as catalyst (2.0 mL, 3500% mol) under microwave heating (120 °C) [23].

The mechanism for the formation of the products has been suggested in Scheme 2 according to the literature [23]. First, 2-hydroxynaphthalene-1,4-dione (1) tautomrizes to intermediate (2). The initial condensation of (2) with o-phenylenediamine (3) afford 6H-benzo[a]phenazin-5-one (4), which in tautomerism equilibrium causes to prepare benzo[a]phenazin-5-ol (5). In addition, standard Knoevenagel condensation of malononitrile (6) and aryl aldehydes (7) in the presence of nano CuO as the catalyst was afforded benzylidenemalononitrile (8). The Michael addition of 6H-benzo[a]phenazin-5-ol (5) with benzylidenemalononitrile (8) formed intermediate (9), which in subsequent cyclization and tautomerism affords the corresponding products (10).

Scheme 2
Suggested mechanism for the formation of 3-amino-2-cyano-1-aryl-1H-benzo[a]pyrano[2,3-c]phenazines.

We also investigated the recycling of the nano CuO as the catalyst under solvent-free conditions using the model reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, 4-chlorobenzaldehyde, and malononitrile (Table 2, Entry 5). After completion of the reaction, the reaction mixture was cooled to room temperature and dissolved in dichloromethane. Then, nano CuO as the catalyst was separated by centrifugation and washed with CH₂Cl₂ for subsequent experiments to check its reusability under similar reaction conditions. The results showed us that nano CuO is a stable catalyst in reaction media and reused several times without significant loss of its catalytic activity (Fig. 1).

Fig. 1
The recycling of the nano CuO as catalyst.

In order to show the accessibility of the present work in comparison with only one reported result in the literature, we summarized some of the results for the preparation of 3-amino-2-cyano-1-(4-chlorophenyl)-1H-benzo[a]pyrano[2,3-c]phenazine in Table 3. The results show that the nano CuO (10 mol%) under solvent-free conditions relative to acetic acid as catalyst (2.0 mL, 3500 % mol) under microwave heating (120 °C) [23], are the most efficient catalysts with respect to the reaction time and exhibits broad applicability in terms of yields.

Entry	Catalyst (mol%)	Conditions	Time (min)	Yield (%)^a [Ref]
1	HOAC (2.0 mL 3500% mol)^b	Microwave heating (120 °C)	10	89 [23]
2	Nano CuO (10 mol%)^c	Solvent-free, 75 °C	7	94 (Present work)

^a Yields refer to isolated pure products and based on the reaction of 2-hydroxynaphthalene-1,4-dione, o-phenylenediamine, 4-chlorobenzaldehyde, and malononitrile.

^b Acetic acid as catalyst is not reusable.

^c The Nano CuO is recyclable catalyst.

3 Conclusion

In this research, nano CuO was used for preparation of 3-amino-2-cyano-1-aryl-1H-benzo[a]pyrano[2,3-c]phenazine derivatives under solvent-free conditions for the first time. The attractive features of this protocol are simple procedure, cleaner reaction, use of reusable nano catalyst. Satisfactory yields of products, as well as a simple experimental, isolation and purification of the products make it a useful protocol for the green synthesis.

4 Experimental

4.1 General

All reagents were purchased from Merck and Aldrich and used without further purification. Copper(II) oxide nanopowder, less than 50 nm particle size was purchased from Sigma-Aldrich chemical company, CAS NO: 1317-38-0. All yields refer to isolated products after purification. The NMR spectra were recorded on a Bruker Avance DPX 300 MHz instrument. The spectra were measured in DMSO-d₆ relative to TMS (0.00 ppm). Melting points were determined in open capillaries with a BUCHI 510 melting point apparatus. TLC was performed on silica-gel Poly Gram SIL G/UV 254 plates.

4.2 General procedure for the synthesis of functionalized benzo[a]pyrano[2,3-c]phenazine derivatives under solvent-free conditions

2-Hydroxynaphthalene-1,4-dione (10 mmol) and o-phenylenediamine (10 mmol) were mixed at 75 °C until a orange solid of benzo[a]phenazine was formed (< 5 min). Then, aryl aldehydes (10 mmol), malononitrile (10 mmol), and nano copper(II) oxide (10 mol%) was added and stirred under thermal conditions at 75 °C for the specific time. After completion of the reaction, monitored by TLC, the reaction mixture was cooled to room temperature. Then, the mixture was diluted with dichloromethane and the catalyst was separated by centrifugation and washed with CH₂Cl₂ (2 × 5 mL) for checking the reusability. The decanted solution containing the product was evaporated to give the yellow solid. The solid was recrystallized with acetone to give the pure yellow solid. All of the desired product(s) were characterized by comparison of their physical data with those of known compounds.

Selected spectra for three known products are given below:

Acknowledgments

We are thankful to the University of Sistan and Baluchestan Research Council for the partial support of this research.

Bibliographie

[1] C.N.R. Rao; A. Müller; A.K. Cheetham The chemistry of nanomaterials: synthesis, properties and applications, Wiley-VCH Verlag & Co., Weinheim, Germany, 2006 (Volume 1)

[2] S.J. Ahmadi; S. Sadjadi; M. Hosseinpour; M. Outokesh; R. Hekmatshoar Catal. Commun., 10 (2009), p. 1423

[3] M.L. Kantam; S. Laha; J. Yadav; S. Bhargava Tetrahedron Lett., 49 (2008), p. 3083

[4] P. Saha; T. Ramana; N. Purkait; M.A. Ali; R. Paul; T. Punniyamurthy J. Org. Chem., 74 (2009), p. 8719

[5] M. Makgatho; R. Anderson; J. O'Sullivan; T. Egan; J. Freese; N. Cornelius; C.V. Rensburg Drug Dev. Res., 50 (2000), p. 195

[6] V. Andrade-Nieto; M. Goulart; J.F.d. Silva; M.J.d. Silva; M. Pinto; A. Pinto; M. Zalis; L. Carvalho; A. Krettli Bioorg. Med. Chem. Lett., 14 (2004), p. 1145

[7] C. Neves-Pinto; V. Malta; M. Pinto; R. Santos; S. Castro; A. Pinto J. Med. Chem., 45 (2002), p. 740

[8] D. Cartwright; W. Chilton; D. Benson Appl. Microbiol. Biotechnol., 43 (1995), p. 211

[9] J. Ligon; S. Dwight; P. Hammer; N. Torkewitz; D. Hofmann; H. Kempf; K. Pee Pest. Manag. Sci., 56 (2000), p. 688

[10] D. Yu; M. Suzuki; L. Xie; S.L. Morris-Natschke; K.H. Lee Med. Res. Rev., 23 (2003), p. 322

[11] F. Borges; F. Roleira; N. Milhazes; L. Santana; E. Uriarte Curr. Med. Chem., 12 (2005), p. 887

[12] J.G. Tangmouo; A.L. Meli; J. Komguem; V. Kuete; F.N. Ngounou; D. Lontsi; V.P. Beng; M.I. Choudhary; B.L.S. Crassiflorone Tetrahedron Lett., 47 (2006), p. 3067

[13] A.S.A. El-Aziz; A.M. El-Agrody; A.H. Bedair; T.C. Corkery; A. Ata Heterocycles, 63 (2004), p. 1793

[14] R.O.S. Kitamura; P. Romoff; M.C.M. Young; M.J. Kato; J.H.G. Lago Phytochemistry, 67 (2006), p. 2398

[15] J.B. Laursen; J. Nielsen Chem. Rev., 104 (2004), p. 1663

[16] G.P. Ellis Chem. Heterocycl. Compd., 31 (1977), p. 1

[17] A. Nefzi; J.M. Ostresh; R.A. Houghten Chem. Rev., 97 (1997), p. 449

[18] L.A. Thompson Curr. Opin. Chem. Biol., 4 (2000), p. 324

[19] A. Dömling Curr. Opin. Chem. Biol., 6 (2002), p. 306

[20] H.R. Shaterian; M. Arman; F. Rigi J. Mol. Liq., 158 (2011), p. 145

[21] H.R. Shaterian; M. Ranjbar; K. Azizi J. Mol. Liq., 162 (2011), p. 95

[22] H.R. Shaterian; M. Ranjbar J. Mol. Liq., 160 (2011), p. 40

[23] S.L. Wang; F.Y. Wu; C. Cheng; G. Zhang; Y.P. Liu; B. Jiang; F. Shi; S.J. Tu ACS Comb. Sci., 13 (2011), p. 135

Cité par

Mohaddeseh Dehnavian; Leila Moradi; Azam Moazeni Bistgani Stepwise synthesis of magnetic mesoporous silica nanoparticles decorated with SnO2 quantum dots as an efficient, recyclable, and green nanocatalyst for the synthesis of benzo[a]pyrano[3,2‐c]phenazine derivatives, Applied Organometallic Chemistry, Volume 38 (2024) no. 9 | DOI:10.1002/aoc.7617
Bubun Banerjee; Arvind Singh; Anu Priya; Manmeet Kaur; Aditi Sharma Synthesis of Structurally Diverse and Biologically Promising Polyheterocycles Involving Benzo[a]phenazin-5-ols, Current Organic Chemistry, Volume 28 (2024) no. 12, p. 914 | DOI:10.2174/0113852728310974240424080252
Farhad Shirzaei; Hamid Reza Shaterian [(EtO)3Si(CH2)3N+H3][CH3COO−] as Basic Ionic Liquid Catalyst Promoted Green Synthesis of Benzo[a]pyrano[2,3-c]phenazine Derivatives in Homogenous Solution, Journal of Solution Chemistry, Volume 53 (2024) no. 2, p. 328 | DOI:10.1007/s10953-023-01332-w
Drashti Shah; Tushar Bambharoliya; Dharti Patel; Krina Patel; Niyati Patel; Afzal Nagani; Vashisth Bhavsar; Anjali Mahavar; Ashish Patel Sustainable Synthesis of Phenazines: A Review of Green Approaches, Current Organic Chemistry, Volume 27 (2023) no. 13, p. 1143 | DOI:10.2174/0113852728257006230921091216
Debjit Das; Sasadhar Majhi Nanoparticles in multicomponent reactions toward green organic synthesis, Nanoparticles in Green Organic Synthesis (2023), p. 75 | DOI:10.1016/b978-0-323-95921-6.00002-0
Mohamed A. El-Atawy; Khaled D. Khalil; Ali H. Bashal Chitosan Capped Copper Oxide Nanocomposite: Efficient, Recyclable, Heterogeneous Base Catalyst for Synthesis of Nitroolefins, Catalysts, Volume 12 (2022) no. 9, p. 964 | DOI:10.3390/catal12090964
Majid Mohammadnia Preparation and characterization of Cu based on 2-(5-Aminopyrimidin-2-yl)pyrimidin-5-amine as novel recyclable metal–organic frameworks for Suzuki reaction, Inorganic Chemistry Communications, Volume 135 (2022), p. 109078 | DOI:10.1016/j.inoche.2021.109078
Hongxia Luo; Majid Mohammadnia Tuning the HOMO and LUMO energy levels of dye sensitizers with electron-accepting capability and electron-drawing capability of substituents to optimize the efficiency of dye-sensitized solar cells: Approach of theoretical, Inorganic Chemistry Communications, Volume 141 (2022), p. 109522 | DOI:10.1016/j.inoche.2022.109522
Farhad Shirzaei; Hamid Reza Shaterian Preparation of novel functionalized ionic liquid: Green, stable, and reusable catalyst for the synthesis of new 2-(phenylsulfonyl)-1H-benzo[a]pyrano[2,3-c]phenazin-3-amine derivatives, Journal of Molecular Liquids, Volume 345 (2022), p. 117893 | DOI:10.1016/j.molliq.2021.117893
Farhad Shirzaei; Hamid Reza Shaterian [(EtO)3Si(CH2)3NH3+][CH3COO−] as a novel basic ionic liquid catalyzed green synthesis of new 2-(phenylsulfonyl)-1H-benzo[a]pyrano[2,3-c]phenazin-3-amine derivatives, Journal of Molecular Structure, Volume 1256 (2022), p. 132558 | DOI:10.1016/j.molstruc.2022.132558
Abolfazl Olyaei; Mahdieh Sadeghpour A review on lawsone-based benzo[a]phenazin-5-ol: synthetic approaches and reactions, RSC Advances, Volume 12 (2022) no. 22, p. 13837 | DOI:10.1039/d2ra02139k
Ankita Chaudhary; Garima Khanna; J.M. Khurana Multicomponent approach for the sustainable synthesis of lawsone-based heterocycles, Green Synthetic Approaches for Biologically Relevant Heterocycles (2021), p. 383 | DOI:10.1016/b978-0-12-820586-0.00016-9
Ateyatallah Aljuhani; Sayed M. Riyadh; Khaled D. Khalil Chitosan/CuO nanocomposite films mediated regioselective synthesis of 1,3,4-trisubstituted pyrazoles under microwave irradiation, Journal of Saudi Chemical Society, Volume 25 (2021) no. 8, p. 101276 | DOI:10.1016/j.jscs.2021.101276
Maryam Farahnak Zarabi; Hossein Naeimi Ultrasound Promoted Synthesis of Benzo[a]pyrano-[2,3-c]phenazines Using Multisulfonic Acid Hyperbranched Polyglycerol Functionalized Graphene Oxide as a Novel and Reusable Catalyst, Polycyclic Aromatic Compounds, Volume 41 (2021) no. 6, p. 1299 | DOI:10.1080/10406638.2019.1672202
Mohsen Nikoorazm; Maryam Khanmoradi; Masoud Mohammadi Guanine‐La complex supported onto SBA‐15: A novel efficient heterogeneous mesoporous nanocatalyst for one‐pot, multi‐component Tandem Knoevenagel condensation–Michael addition–cyclization Reactions, Applied Organometallic Chemistry, Volume 34 (2020) no. 4 | DOI:10.1002/aoc.5504
Mohsen Nikoorazm; Maryam Khanmoradi Application of Cu (II)-Guanine Complexes Anchored on SBA-15 and MCM-41 as Efficient Nanocatalysts for One-Pot, Four-Component Domino Synthesis of Phenazine Derivatives and Investigation of Their Antimicrobial Behavior, Catalysis Letters, Volume 150 (2020) no. 10, p. 2823 | DOI:10.1007/s10562-020-03185-0
Anu Mishra; Yogesh Kumar Pandey; Fatima Tufail; Jaya Singh; Jagdamba Singh A Convenient and Green Synthetic Approach for Benzo[a]pyrano[2,3-c]phenazines via Supramolecular Catalysis, Catalysis Letters, Volume 150 (2020) no. 6, p. 1659 | DOI:10.1007/s10562-019-03057-2
Pallava Nagaraju; Pedavenkatagari Narayana Reddy; Pannala Padmaja; Vinod G. Ugale Synthesis, antiproliferative activity and molecular docking studies of novel benzo[a]pyrano-[2,3-c]phenazine derivatives, Chemical Data Collections, Volume 30 (2020), p. 100541 | DOI:10.1016/j.cdc.2020.100541
Hossein Naeimi; Maryam Farahnak Zarabi Multisulfonate hyperbranched polyglycerol functionalized graphene oxide as an efficient reusable catalyst for green synthesis of benzo[a]pyrano-[2,3-c]phenazines under solvent-free conditions, RSC Advances, Volume 9 (2019) no. 13, p. 7400 | DOI:10.1039/c8ra10180a
Arash Ghorbani-Choghamarani; Masoud Mohammadi; Lotfi Shiri; Zahra Taherinia Synthesis and characterization of spinel FeAl2O4 (hercynite) magnetic nanoparticles and their application in multicomponent reactions, Research on Chemical Intermediates, Volume 45 (2019) no. 11, p. 5705 | DOI:10.1007/s11164-019-03930-0
Ankita Chaudhary; Jitender M. Khurana Synthetic routes for phenazines: an overview, Research on Chemical Intermediates, Volume 44 (2018) no. 2, p. 1045 | DOI:10.1007/s11164-017-3152-8
Nikolaus Guttenberger; Wulf Blankenfeldt; Rolf Breinbauer Recent developments in the isolation, biological function, biosynthesis, and synthesis of phenazine natural products, Bioorganic Medicinal Chemistry, Volume 25 (2017) no. 22, p. 6149 | DOI:10.1016/j.bmc.2017.01.002
Ekane Peter Etape; Lambi John Ngolui; Josepha Foba-Tendo; Divine Mbom Yufanyi; Beckley Victorine Namondo Synthesis and Characterization of CuO, TiO2, and CuO-TiO2Mixed Oxide by a Modified Oxalate Route, Journal of Applied Chemistry, Volume 2017 (2017), p. 1 | DOI:10.1155/2017/4518654
Debjit Das Multicomponent Reactions in Organic Synthesis Using Copper‐Based Nanocatalysts, ChemistrySelect, Volume 1 (2016) no. 9, p. 1959 | DOI:10.1002/slct.201600414
S. Ganesh Babu; R. Karvembu Copper Based Nanoparticles-Catalyzed Organic Transformations, Catalysis Surveys from Asia, Volume 17 (2013) no. 3-4, p. 156 | DOI:10.1007/s10563-013-9159-2

Cité par 25 documents. Sources : Crossref

Commentaires - Politique