2,3-Dichloro-5,6-Dicyanobenzoquinone, DDQ
DDQ (2,3-dichloro-5,6-dicyanobenzoquinone), which is a stronger oxidant than 1,4-benzoquinone, is used as reagent for oxidative couplings and cyclization reactions and dehydrogenation of hydroaromatic compounds.
Recent Literature
Palladium-catalyzed oxygenation of allyl arenes or alkenes produce (E)-alkenyl
aldehydes with high yields. Allylic C-H bond cleavages occur under mild
conditions during this process. Mechanistic studies show that oxygen source is
water.
H. Chen, H. Jiang, C. Cai, J. Dong, W. Fu, Org. Lett., 2011,
13, 992-994.
Alkyl nitrites were prepared in good to excellent yields by treatment of
alcohols and thiols with
triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone/Bu4NNO2 in acetonitrile.
This method allows a selective conversion of primary alcohols in the presence of secondary and tertiary alcohols and thiols.
B. Akhlaghinia, A. R. Pourali, Synthesis,
2004,
1747-1749.
The deprotection of benzyl ethers was effectively realized in the presence of
2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) in MeCN under
photoirradiation using a long wavelength UV light.
M. A. Rahim, S. Matsumura, K. Toshima, Tetrahedron Lett., 2005,
46, 7307-7309.
A tandem TBAB-catalyzed substitution and a subsequent novel oxidative
rearrangement allow the synthesis of aryl or alkenyl nitriles from benzyl
and allyl halides. The broad reaction scope and the mild conditions may make
these methods of use in organic synthesis.
W. Zhou, J. Xu, L. Zhang, N. Jiao, Org. Lett., 2010,
12, 2888-2891.
An inexpensive homogeneous iron catalyst enables a direct approach to alkenyl
nitriles from allylarenes or alkenes. Three C-H bond cleavages occur under the
mild conditions during this process, involving the cleavage of the allyl C(sp3)-H
bond as the rate-determining step.
C. Qin, N. Jiao, J. Am. Chem. Soc., 2010,
132, 15893-15895.
An iron-catalyzed oxidative dehydrogenation enables an α-arylation of
deoxybenzoins with non-prefunctionalized arenes with broad substrate scope and
functional group tolerance. The reaction provides efficient access to
synthetically useful 1,2,2-triarylethanones.
T. Chen, Y.-F. Li, Y. An, F.-M. Zhang, Org. Lett.,
2016, 18, 4754-4757.
An electrocyclic ring closure is the key step of an efficient one-pot synthesis
of pyrrole-2-carboxylates and -carboxamides from chalcones and glycine esters or
amides. The resulting 3,4-dihydro-2H-pyrrole intermediates are oxizided
to the corresponding pyrroles by stoichiometric oxidants or by catalytic
copper(II) and air in good yields.
D. Imbri, N. Netz, M. Kucukdisli, L. M. Kammer, P. Jung, A. Kretzschmann, T.
Opatz, J. Org. Chem.,
2014,
79, 11750-11758.
A reliable method for the direct construction of polysubstituted furans involves
Sn(II)- and Cu(I)-promoted addition/oxidative cyclization of alkynoates and
1,3-dicarbonyl compounds in the presence of
2,3-dichloro-5,6-dicyanobenzoquinone.
W. Liu, H. Jiang, M. Zhang, C. Qi, J. Org. Chem., 2010,
75, 966-968.
The combination of I2/PhI(OAc)2 promotes an
efficient and practical one-pot reaction of amines with alkyne esters and
chalcones under solvent-free ball-milling conditions to afford a variety of
polysubstituted trans-2,3-dihydropyrroles in good yields. This protocol
furnishes the corresponding pyrroles with the addition of DDQ as oxidant in a
subsequent step.
H. Xu, H.-W. Liu, K. Chen, G.-W. Wang, J. Org. Chem., 2018, 83,
6035-6049.
Regioselective hydroamination of alkynes with N-silylamine using a bis(amidate)bis(amido)titanium(IV) precatalyst,
addition of α,β-unsaturated
carbonyls to the crude mixture followed by oxidation affords 47 examples of
pyridines in good yields containing variable substitution patterns, including
pharmaceutically relevant 2,4,5-trisubstituted pyridines.
E. K. J. Lui, D. Hergesell, L. L. Schafer, Org. Lett.,
2018, 20, 6663-6667.
The use of DDQ as an oxidant enables an effective metal-free C-H amination of
N-Ts-2-alkenylanilines to afford a diverse range of substituted indoles.
This operationally simple and robust protocol obviates the need of expensive
transition-metal catalysts, and offers a broad substrate scope. A mechanism
involving a radical cation generated by SET and a migratorial process via a
phenonium ion intermediate is proposed.
Y. H. Jang, S. W. Youn, Org. Lett., 2014,
16, 3720-3723.
Various benzothiazoles were synthesized by the intramolecular cyclization of
thioformanilides using 2,6-dichloro-3,5-dicyano-1,4-benzoquinone (DDQ) in
dichloromethane at ambient temperature in high yields.
D. S. Bose, M. Idrees, B. Srikanth, Synthesis, 2007,
819-823.
A transition-metal-free, DDQ-mediated method enables the intramolecular
S-arylation of o-halobenzothiaoureas to yield 2-aminobenzothiazole
derivatives. The reactions are performed at room temperature under base-free
conditions with very good yields.
R. Wang, W.-j. Yang, L. Yue, W. Pan, H.-y. Zeng, Synlett, 2012, 23,
1643-1648.
A cobalt-catalyzed neutral Diels-Alder reaction of dienes derived from aldehydes
with terminal and internal alkynes, and DDQ oxidation of the dihydroaromatic
intermediates leads to regiochemically enriched biphenyl, terphenyl, and
silyl-functionalized benzene derivatives in good to excellent yields.
G. Hilt, M. Danz, Synthesis, 2008,
2257-2263.
The cobalt-catalyzed Diels-Alder reaction of alkynyl pinacol boronic esters with various dienes generates cycloadducts in very good regioselectivity. A reaction sequence (Diels-Alder reaction, Suzuki coupling, DDQ oxidation) was successfully performed as a one pot operation without isolation of the intermediates.
G. Hilt, K. I. Smolko, Angew. Chem. Int. Ed., 2003, 42,
2795-2797.
The use of [bis(trifluoroacetoxy)iodo]benzene as stoichiometric oxidant and
2,3-dichloro-5,6-dicyano-1,4-benzoquinone as organocatalyst enables a convenient
oxidation of isochromans. A further reaction with grignard reagents or amides
affords the corresponding isochroman derivatives.
W. Muramatsu, K. Nakano, Org. Lett., 2014,
16, 2042-2045.
A facile oxidative coupling of α-carbonyl radicals to
2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) enables the synthesis of
2,3-dicyanofurans and thiophenes from readily available β-diketones, simple
ketones, and β-keto thioamides in very good yield. Mechanistic investigations
revealed that a radical process and a water-promoted C-C bond cleavage could be
involved in this transformation.
Z.-L. Wang, H.-L. Li, L.-S. Ge, X.-L. An, Z.-G. Zhang, X. Luo, J. S. Fossey,
W.-P. Deng, J. Org. Chem., 2014,
79, 1156-1165.
A concise one-pot synthesis of highly functionalized pyridines involves a formal
insertion of rhodium vinylcarbenoids derived from diazo compounds across the N-O
bond of isoxazoles. Upon heating, the insertion products undergo a rearrangement
to give 1,4-dihydropyridines. DDQ oxidation then affords the corresponding
pyridines in good yield.
J. R. Manning, H. M. L. Davies, J. Am. Chem. Soc., 2008,
130, 8602-8603.
A copper-catalyzed tandem reaction of 2-aminobenzamides with tertiary amines
provides quinazolinone derivatives. A broad range of substrates reacted under
the standard conditions to give the corresponding quinazolinone derivatives in
good yields.
W. Xu, X.-R. Zhu, P.-C. Qian, X.-G. Zhang, C.-L. Deng,
Synlett, 2016, 27, 2851-2857.
A facile and efficient intramolecular cyclization of readily available N-aryl
cinnamides is promoted by triflic anhydride in N,N-dimethyl
trifluoroacetamide (DTA) under mild conditions to provide polysubstituted
quinolin-2(1H)-ones.
Q. Zhang, J. Yuan, M. Yu, R. Zhang, Y. Liang, P. Huang, D. Dong, Synthesis, 2017,
49, 4996-5002.
A visible-light photocatalytic aerobic oxidative lactonization of arene C(sp2)-H
bonds provides benzocoumarin derivatives in good yields in the presence of
2,3-dichloro-5,6-dicyano-1,4-benzoquinone and tert-butyl nitrite. This
atom economic method offers mild reaction conditions, use of a green oxidant and
metal-free catalysis.
Y. Wang, S. Wang, B. Chen, M. Li, X. Hu, B. Hu, L. Jin, N. Sun, Z. Shen, Synlett, 2020,
31,
261-266.
