145275-51-0Relevant articles and documents
The reactivity of o-hydroxybenzyl alcohol and derivatives in solution at elevated temperatures
Dorrestijn, Edwin,Kranenburg, Marieke,Ciriano, Maria Victoria,Mulder, Peter
, p. 3012 - 3018 (1999)
The reactivity of o-hydroxybenzyl alcohol (o-HBA, 1), as a model compound for lignin, has been studied in various solvents between 390 and 560 K. Both in polar and apolar solvents the benzylic cation is the reactive intermediate. In alcoholic solvents, the benzylic cation reacts with the solvent to give the corresponding ethers. Relative reaction rates have been determined for different alcohols; a factor of 14 is encountered between the most (methanol) and least (tert-butyl alcohol) reactive ones. The etherification is reversible, in contrast to the electrophilic aromatic substitution with phenol and anisole, for which k(PhOH) = 1 X 105 M-1 s- 1 and k(anisole) = 1 x 104 M-1 s-1, at 424 K. In apolar hydroaromatic solvents, 7H-benz[de]anthracene, 9,10-dihydroanthracene, and 9,10- dihydrophenanthrene, the formation of o-cresol proceeds via hydride transfer from the solvent to the benzylic cation; rate constants at 555 K are 2 x 106, 5 x 104, and 5 x 103 M-1 s-1, respectively.
Reactions of 2-phenyl-4H-1,3,2-benzodioxaborin, a stable ortho-quinone methide precursor
Chambers, Jeffrey D.,Crawford, Jason,Williams, Haydn W. R.,Dufresne, Claude,Scheigetz, John,et al.
, p. 1717 - 1732 (2007/10/02)
Thermolysis of 1-phenyl-4H-1,3,2-benzodioxaborins generated the corresponding ortho-quinone methides, which were found to undergo intermolecular cycloaddition reactions with ethyl vinyl ether, dihydropyran, β-methylstyrene, cyclohexene, and 1-ethoxy-1-trimethylsiloxy-1-propenes to give various substituted chromans.Intramolecular trapping of the quinone methides with an olefin led to the syntheses of several analogs of tetrahydrocannabinols. ortho-Quinone methides, generated by treatment of the 2-phenyl-4H-1,3,2-benzodioxaborins with a Lewis acid, react with various nucleophiles to give the corresponding 1,4-addition products.Thus, alkyl and aryl thiols, alcohols, amine, hydride, allyl trimethylsilane, acetophenone, and diethyl malonate as well as some aryl compounds react with the quinone methide to give various 2-substituted phenols.Intramolecular reaction of the quinone methide with an aryl group led to the preparation of some 4-phenylchromans and tetralins.
