2207-57-0Relevant academic research and scientific papers
Regiodivergent oxidation of alkoxyarenes by hypervalent iodine/oxone system
China, Hideyasu,Tanihara, Kokoro,Sasa, Hirotaka,Kikushima, Kotaro,Dohi, Toshifumi
, p. 2 - 8 (2020)
We have found that the combination of Oxone with an organoiodine compound, i.e., 2-iodobenzoic acid (2-IB), selectively yields p-quinones from monomethoxyarenes under mild conditions. In this reaction system, an organoiodine compound is immediately oxidized by Oxone to generate cyclic hypervalent iodine (III) species in situ, which serves as the specific mediator for the selective p-quinone synthesis, preventing o-quinone formation.
Lewis Acid-Directed Reactions of Quinones with Styrenyl Systems: The Case of 2-Methoxy-3-methyl-1,4-benzoquinone
Engler, Thomas A.,Iyengar, Rajesh
, p. 1929 - 1934 (1998)
Reactions of 2-methoxy-3-methyl-1,4-benzoquinone with various (E)-1-propenylbenzenes promoted by 1 equiv of Ti(IV), as a 1:1 mixture of TiCl4-Ti(O-i-Pr)4, produce rel-(1S,6R,7R,8R)-8-aryl-4,7-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5- diones 3 and trans-2-aryl-3,7-dimethyl-6-methoxy-2,3-dihydro-5-benzofuranols 5 as the major products. Reactions promoted by 2 equiv of Ti(IV) as a 1:1 mixture of TiCl4-Ti(O-i-Pr)4 or 1 equiv of either TiCl4, SnCl4, or BF3·OEt2 give regioisomeric rel-(1R,6S,7A,8R)-7-aryl-4,8-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5- diones (4) and/or trans-2-aryl-3,6-dimethyl-7-methoxy-2,3-dihydro-5-benzofuranols (6). A mechanism involving regioselective coordination of the various Lewis acids to the quinone is used to explain the formation of the products. These reactions demonstrate the effective regiocontrol exerted over the reactions by the nature of the Lewis acid promoters. Cyclobutanes 3 and 4 cleanly undergo rearrangement to the corresponding benzofuranols 5 and 6 on treatment with protic acid. In contrast, reactions of 2-methoxy-1,4-benzoquinone promoted by either BF3·OEt2 or Ti(IV), as 1 equiv or excess amounts of TiCl4 or 1:1 TiCl4-Ti(O-i-Pr)4, all afford the same regioisomeric products, i.e., rel-(1S,6R,7R,8R)-8-aryl-7-methyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5-dione 25 and/or trans-2-aryl-3-methyl-6-meth-oxy-2,3-dihydro-5-benzofuranol 27.
Combined C-H activation/cope rearrangement as a strategic reaction in organic synthesis: Total synthesis of (-)-colombiasin A and (-)-elisapterosin B
Davies, Huw M. L.,Dai, Xing,Long, Matthew S.
, p. 2485 - 2490 (2006)
The total synthesis of (-)-colombiasin A (2) and (-)-elisapterosin B (3) has been achieved. The key step is a C-H functionalization process, the combined C-H activation/Cope rearrangement, between methyl (E)-2-diazo-3-pentenoate and 1-methyl-1,2-dihydrona
Laccase-mediated synthesis of 2-methoxy-3-methyl-5-(alkylamino)- and 3-methyl-2,5-bis(alkylamino)-[1,4]-benzoquinones
Herter, Susanne,Michalik, Dirk,Mikolasch, Annett,Schmidt, Marlen,Wohlgemuth, Roland,Bornscheuer, Uwe,Schauer, Frieder
, p. 91 - 97 (2013/05/21)
The synthesis of 5-alkylamino- and 2,5-bis(alkylamino)-[1,4]-benzoquinones, showing structural similarity to natural mitomycins, was performed through coupling of 2-methoxy-3-methylhydroquinone with primary amines such as n-octylamine, geranylamine and cy
Efficient and green telescoped process to 2-methoxy-3-methyl-[1,4] benzoquinone
Rodriguez Gonzalez, Raquel,Gambarotti, Cristian,Liguori, Lucia,Bjorsvik, Hans-Rene
, p. 1703 - 1706 (2007/10/03)
A telescoped process for the preparation of 2-methoxy-3-methyl-[1,4] benzoquinone is disclosed. When this novel process is compared to the prevailing method that utilizes Na2Cr2O7 as the oxidant, the novel process represen
Access to orthogonal protected phenols - Synthesis of a silylated quinol
Siddiqi, Shahzad A.,Heckrodt, Thilo J.
, p. 328 - 331 (2007/10/03)
Herein we describe the synthesis of t-butyldimethylsilyl protected quinol (9), using an oxidation/reduction sequence to create the desired orthogonality. The title compound acts as a synthetic equivalent for a quinone, required in the total synthesis of E
Total synthesis of elisabethin A: Intramolecular Diels-Alder reaction under biomimetic conditions
Heckrodt, Thilo J.,Mulzer, Johann
, p. 4680 - 4681 (2007/10/03)
We describe the first total synthesis of the marine diterpenoid elisabethin A. The synthesis uses (S)-hydroxy-2-methyl-propionate as the chiral starting material, which is elaborated into a dienyl-iodide and added to an aryl acetic acid ester via enolate
Indoloquinones, part 7. Total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C by an intramolecular palladium-catalyzed oxidative coupling of an anilino-1,4-benzoquinone
Kn?lker, Hans-Joachim,Fr?hner, Wolfgang,Reddy, Kethiri R.
, p. 557 - 564 (2007/10/03)
A highly efficient total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C is presented. The key-step is a palladium(II)-catalyzed oxidative cyclization of an anilino-1,4-benzoquinone to a carbazole-1,4-quinone which proceeds in up to 91% yield. Using this approach the natural product is obtained in four steps and 39% overall yield starting from aniline.
Palladium-catalyzed total synthesis of the antibiotic carbazole alkaloids carbazomycin G and H
Knoelker, Hans-Joachim,Froehner, Wolfgang
, p. 173 - 175 (2007/10/03)
A highly efficient palladium-catalyzed synthesis affords carbazole-1,4-quinones which can be transformed directly into the carbazomycins G and H and are shown to represent precursors for several other biologically active carbazole alkaloids.
Ultrasound-promoted synthesis of substituted phenanthrene-1,4-quinones; the structure of plectranthon D
Zhang, Zhao-Rong,Flachsmann, Felix,Moghaddam, Firouz Matloubi,Rueedi, Peter
, p. 2153 - 2156 (2007/10/02)
A series of tanshinone-type diterpenoids was prepared by ultrasound-promoted and Lewis acid catalyzed, highly regioselective cycloadditions of styrenes with substituted 1,4-benzoquinones as the key step.
