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OXIDATION OF AROMATIC SYSTEM benzene and phenols

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OXIDATION OF AROMATIC SYSTEM benzene and phenols Powered By Docstoc
					OXIDATION OF AROMATIC SYSTEM,
PHENOLS AND QUINONES

INTRODUCTION

Oxidation:-
              The process of oxidizing; the addition of oxygen to a compound with a loss
of electrons; always occurs accompanied by reduction. During oxidation there is loss of
at least one electron when two or more substances interact. Those substances may or may
not include oxygen.

Examples of oxidation include burning and rusting although, both occur at very different
speeds. Oxidation reactions are also known as Redox (the word come from reduction-
oxidation) reactions, those in which the oxidation number of atoms is altered.




                       Illustration of a redox reaction

Example:


For example, in the reaction between iron and copper(II) sulphate solution:



The ionic equation for this reaction is:



As two half-equations, it is seen that the iron is oxidized:


                                                                                      1
And the copper is reduced:



Oxidizing agents are substances which bring about the oxidation of other substances, e.g.
potassium permanganate, potassium dichromate, nitric acid, hydrogen peroxide, etc.




Oxidation of aromatic system, phenols and quinines:-


Oxidation of aromatic system ( simple arrenes):-


Aerobic oxidation of alkyl arenes is a promising subject in industrial chemistry. Many
bulk chemicals such as benzoic acid, terephthalic acid, isophthalic acid etc. are
manufactured by homogeneous liquid phase oxidation with air (O2). These oxidation
processes are usually operated at more severe temperature (175–225 °C) and higher
pressure of air (15–30 atm) in the presence of a mixture of Co(OAc)2/Mn(OAc)2 and
bromine, typically in the form of HBr, NaBr or tetrabromoethane in acetic acid as a
solvent. Due to corrosive bromine vessels lined with titanium or other expensive metals is
necessary .



oxidation of alkyl arenes and develop easy and fast approaches for the synthesis of
metallophthalocyanines, herein we report a simple and convenient method for the aerobic
oxidation of primary and secondary benzilic C–H compounds to their corresponding
ketones or carboxylic acid under the neutral and mild reaction conditions using a
combined of N-hydroxyphthalimide (NHPI) and cobalt(II) tetrasulfophthalocyanine
([CoTSPc]4−) supported on silica.




                                                                                        2
PRIMARY REFERENCE:


Reduction of ketones containing a perfluoroalkyl group by bromomagnesium
ethylate. Makarov, A. M.; Shadrina, L. P.; Dormidontov, Yu. P. USSR. Sintezy na Osnove Magnii- i
Tsinkorganich. Soedin., Perm (1980),  48-56. From: Ref. Zh., Khim. 1981, Abstr. No. 11Zh395. Journal
written in Russian. CAN 95:114703 AN 1981:514703 CAPLUS




                   +     HO2C-(CF2)5-CF3
Br                                                                               (CF2)5-CF3
     Mg      Me                                                   Me
                                                                             O



EXAMPLES

Oxidation of cumene involves an air-oxidation, inexpensive hydrocarbon that may be
obtained by alkylation of benzene with propylene. The air-oxidation of cumene results in
the formation of cumene hydroperoxide with on acid catalysed decomposition yield ph




                                                                                                  3
REACTION
                                                                                                     O OH
                                                         H3C            CH3                    H3C     CH3
                                                                                                                             OH
                                         H2SO4                                 O2                            H2SO4
       +       CH3CH=CH2                                                                                                          +
                                                                                       0
                                          250 OC                                  130 C                       70 0C


                                                                                                                              CH3COCH3




Mechanism
                                                                                                     H3C     CH3
                                                               H         CH(CH3)2

2.                     +   CH3CHCH3

                                                                                  -H           .
                                                                                               O
     H3C       CH3                                 .                                       O
                                            H3C        CH3                        H3C          CH3
                               .
                           R                                       O2
3.
                           -RH

                   .
               O
           O                                                       O OH
     H3C       CH3                 H3C   CH3                 H3C     CH3          H3C      .   CH3

4.                                                                            +
                           +



Decomposition of cumene hydroperoxide involves into hydrolytic rearrangement

                                                                              H3C                            H3C
           O OH                                CH3                                                                     OH2
5.   H3C     CH3                         H3C                                           C                           C
                                                 O OH2                        H3C          O                 H3C       O
                           H                                                                          H2O


                                                        -H2O




                                                                                                                                      4
                                     ..
         H3C                    H3C   OH
                   OH2
               C                    C
         H3C       O            H3C     O H              OH

6.                                                                       CH3              CH3
                                                               + H3C C              H3C
                                                                                          C
                                                                         OH    -H         O




Oxidation of antheracene to quinone.



                                                     O
                         CrO2




                                                     O




Hydroxylation of aromatic ring.

It is rather difficult to add an oxygen atom to a benzene ring by normal electrophilic
substitution reaction as there is no good reagent for "OH".A Nitrogen atom can be added
easily by nitration and reduction and diazotization provide a way of replacing the nitro
group by an hydroxyl group.




                                        X
                                                          N2
                         NO2            NH2                              OH
           HNO3                 H2                             H2O
                                              NaNO2
                                              HCl,             Heat
               H2SO4            Pd/C                 0
     R                   R                    H2O,5 C
                                        R                 R              R




                                                                                           5
Selective Oxidation at Carbon Adjacent to AromaticSystems with IBXK. C.
Nicolaou,* Phil S. Baran, and Yong-Li Zhong J. Am. Chem. Soc. 2001, 123, 3183-
3185

A number of new synthetic technologies based on the reactivityof the periodinane
reagents DMP and IBX. On the basis of mechanistic rationales, It was hypothesized that
benzylic positions could beoxidized by IBX via a SET mechanism.


          IBX                                          .    IBX
R                   R                      R                       R
                           .                               SET
         SET

          -H
                                                                           H2O


                                               O
                                                             IBX
                                                   H                             OH
                                       R                               R




                                                                                      6
RECENT EXAPPLE:

Organic Letters, 10(19), 4323-4326; 2008



                                          Br                                            OMe
  S                              S             S                              MeO
           Br                                       + (i-Pr)3Si     C CH +
                + Bu3 SnCl   +                                                                  OH +
                                                                                              B
      Me                             Br                                                       OH

  I               Br
                        S                 BuLi,KF,Bromosuccinimide,AcOH,NaHClO3,
                             Sn (Bu-n)3   Et3N,TMEDA,I2,K2CO3, PdCl2(PPh3)2,CuI,
 Br              +
           I
                                           Pd(PPh3)4,Et2O,Hexane,DMF,CHCl2,H2O,T
                                           HF,CHCl3


                                                                                        MeO
                                                        (i-Pr)3Si
                                                                    C                  MeO
                                                                     C
                                                                                         S
                                                                              S                   Me

                                                                    OMe
                                                                                              S       Si ( Pr-i )3
                                                                          S                       C C
                                                    MeO
                                                                                  Me




Oxidation of aromatic system (phenols and quinones):-

Phenol is one of the most important chemicals in the field of industrial chemistry.
Term phenol is commonly used in the context of hydroxyl benzene, which is liquid at
room temperature when contaminated with water than is carbolic acid of pharmacy.
Phenol primarily converted into phenolic resins, bisphenol-A, caprolactam, adipic acid
and plasticizers. Direct oxidation of benzene to phenol is of great interest not only for its



                                                                                                                     7
industrial importance, but also from a purely scientific point of view. Although a direct
oxidation process of benzene to phenol would be the most economical route.

Phenols are rather easily oxidized despite the absence of a hydrogen atom on the
hydroxyl bearing carbon. In genral phenols are more easily oxidized than simple
alcohols. Oxidation can be achieved by reaction with silver oxide(Ag2O) or chromic acid
(Na2Cr2O7) or other oxidizing agents.

Particularly the oxidation of 1,2- and 1,4- benzendiols and other derivatives. The
carbonyl compounds from the oxidation of phenol by7 chromic acid is the much
important.



       Example:

  OH                            O
          Na2Cr2O7

           H2SO4
  OH                            O




Recent example:-

The polyoxometalate (POM) oxidation of phenols.

Polyoxometalates (POMs) are a rapidly growing class of metal-oxygen-cluster anions.[1
– 4] They are synthetic inorganic compounds that contain highly symmetrical core
assemblies of MO(x) units (M = Vanadium, Molybdenum, Tungsten) and react as outer-
sphere electron-transfer oxidants and catalysts. The properties of POMs can be controlled
by altering the POM composition and structure. As a result, polyoxometalates have found
applications in analytical and clinical chemistry, catalysis (including photocatalysis),
biochemistry (electron transport inhibition), medicine (anti-tumor, anti-viral, and even
anti-HIV activity), and solid-state devices.


                                                                                        8
Reaction:
                                                                       O


      R
              POMOX(SIVW11O40)5-
                                                  POMred
                                                                             R

  O

                        POMred(SIVW11O40)6-
                                                                       O
          e                                   POMox
                                                           FAST
              -H



                                              R




                                         O

                                                      FAST

            -e                  POMred
                   K2


      R                                                           Radical coupling +
                 POMox                                            Poloyphenols

  O



Scheme 1. Possible reaction mechanism for POM (SiVW11O40)5- oxidation of phenols.

This is consistent with an electron-transfer reaction mechanism. The better correlation
between rate data and σ+ (r2 =0.98) values as compared to σ (r2 =0.88) support an
electronic deficient intermediate in the transition state and a reaction mechanism leading
to the formation of an electron-deficient phenoxy radical (Scheme 1). The strong
correlation with σ+ is further an indication that the reaction mechanism of all phenols
oxidized by POM is essentially the same.

Mechanism:-




                                                                                        9
          O                                   O                         O              O                                        O




                        POM                                                                          POMOX
                                                                                                      -e
                       -e, -H


         OH                                   O                         O              O                                        O

                                                                       DIMERIZATION
                                                                                                                                    H2O


          O                  O                               O                O                  O
                                                                                                                       HO            O



                                              POM0X
                                                                                                             - CH3OH
                                           -e, - H


          OH                 O                               OH               OH                 O    (10) 3%                   O
                                                                  (12) 0.7%
                                               POMOX
                                                                  O                O                     O                  O
                                         -e


                                                                                       - CH3OH
Pilimerization by coupling with radical intermediate
                                                                                           H2O

                                                  (11) 27%
                                                                  OH               O                     OH                 O




Scheme 2. Possible mechanism for the POM (SiVW11O40)5- oxidation of 1 under
Anaerobic conditions.

The first step in the reaction of 1 with POM is oxidation of the phenolic substrate. This
likely involves either hydrogen atom transfer or protoncoupled electron transfer
mechanisms. The resonance stabilized phenoxy radical intermediate then undergoes (i)
reaction with a second POM and further oxidation to the corresponding cation and
subsequent benzoquinone formation (10), or (ii) radical coupling with a second oxidized
phenol and dimmer formation (12). The resulting dimeric compound is then rapidly
oxidized, and undergoes the same oxidative reaction steps as the initial phenol, leading to
oxidized biphenols (11) and other coupling products. In reactions run under the
conditions used for kinetic analysis (1:49, POM: phenol) only oxidized phenolic products
were detected. However, when product analyses were performed on reactions run in an
excess of POM relative to phenol (4:1, POM: phenol), the primary products detected
were oxidative coupling products, which precipitated during the reaction. In fact, the
yield of precipitated material was approximately 40, 50, and 70 wt% of the reaction
products detected from 1, 4, and5, respectively.

Reference:

         Polyoxometalate (POM) Oxidation of Phenols: Effect of Aromatic Substituent
          Groups on Reaction Mechanism Yong Sik Kim a; Hou-min Chang b; John F.
          Kadla.




                                                                                                                                          10
RECENT EXAMPLES:-

EXAMPLE 01:

Evidence for Concerted Proton-Electron Transfer in the Electrochemical
Oxidation of Phenols with Water As Proton Acceptor. Tri-tert-butylphenol.
Cyrille Costentin, Cyril Louault, Marc Robert, and Jean-Michel Save´ ant*
Contribution from the Laboratoire d’Electrochimie Mole´culaire, Unite´ Mixte de
Recherche UniVersite´ - CNRS No
7591, UniVersite´ Paris - Diderot, Baˆtiment LaVoisier, 15 rue Jean de Baı¨f, 75205
Paris Cedex 13, France




EXAMPLE 02

Efficient ortho-Oxidation of Phenols with Diacyl Peroxides
Masahiro TADA,* Risa ISHIGURO, and Ryohei IZUMI
Laboratory of Bioorganic Chemistry, Tokyo University of Agriculture and Technology;
Fuchu, Tokyo 183–8509, Japan.
Received July 5, 2007; accepted December 22, 2007; published online January 8, 2008




                                                                                 11
  OH                                    Cl          OH         O
                 Cl                                                           Cl
                        O   O                            O                         OH
         R   +                                                            +
                        O




                            O
                                                                                   O
                                                                     Cl



EXAMPLE 03

Studies on the catalysis by lithium perchlorate and lithium trifluoromethanesulfonate of
the photo-oxidation of phenols and a-phellandrene in different solvents WOJCIECH J.
KINART*, ANDRZEJ KINART and MONIKA KOZAK
Department of Organic Chemistry, University of Lodz,
Narutowicza 68,90-136, Lodz, Poland
(Received 3 March 2007; in final form 4 May 2007)




EXAMPLE 04

Regioselective Oxidation of Phenols to o-Quinones with o-Iodoxybenzoic Acid (IBX)
Derek Magdziak, Andy A. Rodriguez,† Ryan W. Van De Water, and Thomas R. R.
Pettus*




                                                                                       12
                                   O

                                       O
                                   I                  O                            OAc
            OH                         O                                                 OAc
                              HO                           O    H2/Pd/C


  Y                                              Y                            Y
                                                               K2CO3,Ac2O
      Z                                               Z                            Z




REFERENCES
 1. Synthesis and application of polymer-bound IBX toward the oxidation of phenols to o-quinones.
    Abstracts of Papers, 235th ACS National Meeting, New Orleans, LA, United States, April 6-10, 2008
    (2008), CHED-458. Publisher: (American Chemical Society, Washington, D. C) CODEN:69KNN3



 2. Sodium percarbonate on montmorillonite K10: an ecofriendly and efficient supported reagent for
    oxidation               of                 phenols                 to               quinones.
    Organic Chemistry (Rajkot, India) (2006), 2, (5-6), 110-112. Publisher: (Trade Science Inc., )
    CODEN:OCRIA7



 3. First asymmetric oxidation of phenols to ortho-quinols using a new class of enantioselective
    oxidants.
    Abstracts of Papers, 234th ACS National Meeting, Boston, MA, United States, August 19-23, 2007
    (2007), ORGN-389. Publisher: (American Chemical Society, Washington, D. C) CODEN:69JNR2



 4. Phenolic content and antioxidant capacity of Philippine sweet potato (Ipomoea batatas) varieties.
    Food Chemistry (2009), 113, (4), 1133-1138. Publisher: (Elsevier B.V., ) CODEN:FOCHDJ ISSN:0308-
    8146.




                                                                                                  13
5. Limoncella' apple, an Italian apple cultivar: Phenolic and flavonoid contents and antioxidant
   activity.
   Food Chemistry (2007), 104, (4), 1333-1337. Publisher: (Elsevier B.V., ) CODEN:FOCHDJ ISSN:0308-
   8146.



6. Selective oxidation of benzene to phenol over H-ZSM-5 catalyst: role of mesoporosity on the
   catalyst                                                                              deactivation.
   Studies in Surface Science and Catalysis (2008), 174B, (Zeolites and Related Materials), 1203-1206.
   Publisher: (Elsevier B.V., ) CODEN:SSCTDM ISSN:0167-2991.



7. Wet                    Air                Oxidation                       of                   benzene.
   Avail. UMI, Order No. DANR38555. (2007), 122 pp. From: Diss. Abstr. Int., B 2008, 69(5), 3136.



8. Ternary metal oxide catalysts for selective oxidation of benzene to phenol.
   Journal of Industrial and Engineering Chemistry (Seoul, Republic of Korea) (2008), 14, (5), 596-601.
   Publisher: (Korean Society of Industrial and Engineering Chemistry, ) CODEN:JIECFI ISSN:1226-086X.

9. Oxidation of Benzene Catalyzed by 2,2'-Bipyridine and 1,10-Phenantroline Cu(II) Complexes.
   Catalysis Letters No pp. yet given. Publisher: (Springer, ) CODEN:CALEER ISSN:1011-372X.


10. Direct mild partial oxidation of benzene and methane in catalytic and photocatalytic membrane
    reactors.
    DGMK Tagungsbericht (2008), 2008-3, (Preprints of the DGMK-Conference "Future Feedstocks for Fuels
    and Chemicals", 2008), 217-224. Publisher: (Deutsche Wissenschaftliche Gesellschaft fuer Erdoel,
    Erdgas und Kohle, ) CODEN:DGTAF7 ISSN:1433-9013.



11. Research     progress      on    direct    catalytic    oxidation   of  benzene   to  phenol.
    Fenzi Cuihua (2008), 22, (4), 379-384. Publisher: (Kexue Chubanshe, ) CODEN:FECUEN ISSN:1001-
    3555.



12. Mechanisms for the Ni+-mediated oxidation of benzene to phenol by N2O.
    Chemical Physics Letters (2008), 463, (1-3), 54-59. Publisher: (Elsevier B.V., ) CODEN:CHPLBC
    ISSN:0009-2614.



13. The aldo-keto reductase AKR1C3 contributes to 7,12-dimethylbenz(a)anthracene-3,4-dihydrodiol
    mediated oxidative DNA damage in myeloid cells: Implications for leukemogenesis.         Birtwistle,
    Jane; Hayden, Rachel E.; Khanim, Farhat L.; Green, Richard M.; Pearce, Claire; Davies, Nicholas J.;
    Wake, Naomi; Schrewe, Heiner; Ride, Jonathan P.; Chipman, James K.; Bunce, Chris M.      School of
    Biosciences, University of Birmingham, Edgbaston, Birmingham, UK.              Mutation Research,
    Fundamental and Molecular Mechanisms of Mutagenesis (2009), 662(1-2), 67-74. Publisher: Elsevier
    B.V., CODEN: MUREAV ISSN: 0027-5107.




                                                                                                       14
14. Studies on vanadium catalyzed direct hydroxylation of aromatic hydrocarbons using hydrogen
    peroxide as oxidant.   Joseph, Jomy K.; Singhal, Sweety; Jain, Suman L.; Sivakumaran, R.; Kumar,
    Basant; Sain, Bir. Chemical and Biotechnology Division, Indian Institute of Petroleum, Mokhampur,
    Dehra Dun, India. Catalysis Today (2009), 141(1-2), 211-214. Publisher: Elsevier B.V., CODEN:
    CATTEA ISSN: 0920-5861.




15. Selective oxidation of aromatic amines to nitro derivatives using potassium iodide-tert-butyl
    hydroperoxide catalytic system.       Reddy, K. Rajender; Maheswari, C. Uma; Venkateshwar, M.;
    Kantam, M. Lakshmi.      Inorganic and Physical Chemistry Division, Indian Institute of Chemical
    Technology, Hyderabad, India. Advanced Synthesis & Catalysis (2009), 351(1+2), 93-96. Publisher:
    Wiley-VCH Verlag GmbH & Co. KGaA, CODEN: ASCAF7 ISSN: 1615-4150.




                                                                                                  15

				
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