2,3-Dichloro-5,6-Dicyanobenzoquinone (DDQ). A New Preparation

Walker, Derek; Waugh, Thomas D.

doi:10.1021/jo01020a529

Cited by 29 publications

(9 citation statements)

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“…Under these conditions, the desired product 3 aa was obtained in almost quantitative yield (Table 1, entry 3). The results demonstrated that the amount of DDQ had not been sufficient in our initial studies (Table 1, entries 1 and 2), and presumably one equivalent of DDQ was decomposed15b, 17 by each equivalent of water formed during the reaction. We next examined the reaction at a lower temperature of 50 °C, whereupon the yield was reduced to 81 % (Table 1, entry 4).…”

Section: Resultsmentioning

confidence: 83%

Transition‐Metal‐Free One‐Pot Synthesis of Biaryls from Grignard Reagents and Substituted Cyclohexanones

Zhou

Simon

2013

Chemistry A European J

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Section: Resultsmentioning

confidence: 83%

Transition‐Metal‐Free One‐Pot Synthesis of Biaryls from Grignard Reagents and Substituted Cyclohexanones

Zhou

Simon

2013

Chemistry A European J

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“…Tetrachlorohydroquinone (TCQH 2 ), was obtained from Sigma. 2,3-Dichloro-5,6-dicyano-1,4-hydroquinone (DDQH 2 ) was synthesized by reduction of DDQ with aqueous sodium bisulfite in toluene [20]. The µ-oxo(1) and µ-oxo(2) dimers of FePc, (FePc) 2 O were synthesized following literature procedures [6,7].…”

Section: Methodsmentioning

confidence: 99%

Investigation of Phthalocyanine Catalysts for the Aerobic Synthesis of meso-Substituted Porphyrins

Ravikanth

Achim

Tyhonas

et al. 1997

J. Porphyrins Phthalocyanines

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The aerobic oxidation process for the synthesis of porphyrins, previously performed using 5 mol % p-chloranil (TCQ), 5 mol % iron(II) phthalocyanine ( FePc ) and stoichiometric amounts of O 2, has been refined using new phthalocyanine catalysts. Four phthalocyanine catalysts have been prepared, characterized by Mössbauer spectroscopy and examined for efficacy in the high concentration (0.1 M) synthesis of tetraphenylporphyrin at room temperature. Each phthalocyanine has been identified to be a μ-oxo dimer. Two catalysts are soluble (the μ-oxo dimers [(t-butyl)4 FePc ]2 O and [(n- C 6 H 13 O )4 FePc ]2 O ) and enable homogeneous reactions, while two are insoluble (the μ-oxo(1) and μ-oxo(2) dimers of FePc , ( FePc )2 O ) and give heterogeneous reactions. These four phthalocyanine compounds provide efficient catalysis at the 0.3–1 mol % level using only 1 mol % quinone or hydroquinone ( TCQ , DDQ , TCQH 2 or DDQH 2), affording ~25% yields of tetraphenylporphyrin in 60 min of oxidation. There are no discernible advantages of the homogeneous versus heterogeneous catalysts. The μ-oxo dimers are active, but FePc is inactive, at the 0.3 mol % level. The activity of the FePc sample at the 5 mol % level is attributed to residual μ-oxo dimer impurity. This aerobic oxidation process is superior to stoichiometric oxidation with TCQ or DDQ , and can be performed in the presence of BF 3· O ( Et )2, trifluoroacetic acid, or under neutral conditions.

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“…The rather expensive DDQ can be recovered easily as described in a recent publication . The use of 2,3,5,6-tetrachloro-benzoquinone took either longer reaction time or gave even unchanged starting 8.53(s,2H,ArH) ['I. 8.34 (s,2H,ArH),…”

Section: Pawlowski and M A C Kmentioning

confidence: 99%

“…8.04(s,2H,ArH) [bl . 8.32(s,2H,ArH) ['I. 3.33(S,lH,NH), 8.49(s,2H,ArH), 9.03 After cooling, the mixture was diluted with water and filtered.…”

Section: Pawlowski and M A C Kmentioning

confidence: 99%

A Convenient Synthesis of Trifluoromethyl Substituted Phthalocyanines

Pawlowski

Hanack

1981

Synthetic Communications

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2,3-Dichloro-5,6-Dicyanobenzoquinone (DDQ). A New Preparation

Cited by 29 publications

References 0 publications

Transition‐Metal‐Free One‐Pot Synthesis of Biaryls from Grignard Reagents and Substituted Cyclohexanones

Transition‐Metal‐Free One‐Pot Synthesis of Biaryls from Grignard Reagents and Substituted Cyclohexanones

Investigation of Phthalocyanine Catalysts for the Aerobic Synthesis of meso-Substituted Porphyrins

A Convenient Synthesis of Trifluoromethyl Substituted Phthalocyanines

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