14387-13-4Relevant articles and documents
Construction of vicinal quaternary carbons via Cu-catalyzed dearomative radical addition
Tsuchiya, Naoki,Nishikata, Takashi
, p. 718 - 721 (2019)
In this paper, we confirmed the dearomative addition of tertiary alkyl radicals onto BHT derivatives to form highly congested vicinal quaternary carbons to produce tert-alkylated styrenes in the presence of copper catalyst. Although there are three candid
The Reaction of the 2,6-Di-tert-butyl-4-methylphenoxy Radical with Phenols
Omura, Kanji
, p. 921 - 927 (2007/10/02)
Dimer 3 dissociates in solution to give the phenoxy radical 4.When solid 3 is dissolved in a solution of phenol 11a, radical 4 dehydrogenates the phenol to afford phenol 5 and phenoxy radical 12.Radical 12 couples with more 4 to afford principally bis(cyclohexadienone) 16a and a minor amount of the dimeric bis(cyclohexadienone) 13.The preferential formation of 16a over 13 is explained as the result of a solvent-cage reaction.Compounds 13 and 16a are isomerized in the presence of silica gel or triethylamine to 4,4'-dihydroxybiphenyl 14 and phenolic dienone 17a, respectively.Compound 13 is relatively stable in hexane at 30 deg C, while 16a slowly dissociates under these conditions to afford parent radicals 4 and 12.If 11a is present, radical 4 either recombines with 12 or dehydrogenates the phenol.Two radicals of 12 generated by the dissociation of 16a and the subsequent dehydrogenation of 11a couple to give 13.Therefore, dissolving 3 in hexane containing excess 11a and keeping the resulting solution at 30 deg C results in the preferential formation of 13.Dissolving 3 in triethylamine containing phenols 11 or 21 similarly affords dienones 17 or 23.The yields of these dienones increase with increasing electron-donating capability of the substituent of the phenol ring.
Unsymmetrical Anodic C-C Coupling of 2,6-Di-tert-butyl-4-methylphenol
Ohmori, Hidenobu,Ueda, Chihiro,Nakagawa, Toshiko,Nishiguchi, Susumu,Jeong, Jisook,Masui, Masaichiro
, p. 508 - 515 (2007/10/02)
Cyclic voltammetry of 2,6-di-tert-butyl-4-methylphenol (1) in acetonitrile in the presence of an aliphatic amine such as ethyl-, diethyl-, or triethylamine shows an ill-defined anodic wave - a socalled kinetic wave - around 0.5V vs. aqueous saturated calomel electrode, indicating an electron-transfer process preceded by a slow chemical reaction.Based on the estimated pKa value of 1 (pKa=12.55 in water at 25 deg C), the chemical reaction was ascribed to a slow hydrogen-bonding association of 1 and the added amine.Controlled potential electrolysis of 1 at the potential of the anodic wave gave an unsymmetrical dimer, 2,6-di-tert-butyl-4-(3,5-di-tert-butyl-4-hydroxyphenyl)-4-methyl-2,5-cyclohexadiene-1-one, as the main product.Side-chain aminated derivatives of 1, Ar-CH2NHEt, Ar-CH2NEt2, and Ar-CH2N+NEt3 (Ar=3,5-di-tert-butyl-4-hydroxyphenyl), are suggested to be the intermediates; that is, the process of dimer formation is explained in terms of cross-coupling of the phenoxyl radicals derived from 1 and the side-chain aminated phenols followed by expulsion of the aminomethyl group.Keywords - electrochemical oxidation; cyclic voltammetry; conrolled potential electrolysis; 2,6-di-tert-butyl-4-methylphenol; oxidative dimerization; phenol coupling