Structural effects on the OH–-promoted fragmentation of methoxy-substituted 1-arylalkanol radical cations in aqueous solution: the role of oxygen acidity was written by Baciocchi, Enrico;Bietti, Massimo;Gerini, Maria Francesca;Manduchi, Laura;Salamone, Michela;Steenken, Steen. And the article was included in Chemistry – A European Journal in 2001.Recommanded Product: 3-(3,4-Dimethoxyphenyl)propan-1-ol This article mentions the following:
A kinetic and product study of the OH–-induced decay in H2O of the radical cations generated from some di- and tri-methoxy-substituted 1-arylalkanols [ArCH(OH)R·+] and 2- and 3-(3,4-dimethoxyphenyl)alkanols has been carried out by using pulse- and γ-radiolysis techniques. In the 1-arylalkanol system, the radical cation 3,4-(MeO)2C6H3CH2-OH·+ decay at a rate more than two orders of magnitude higher than that of its Me ether; this indicates the key role of the side-chain OH group in the decay process (oxygen acidity). However, quite a large deuterium kinetic isotope effect (3.7) is present for this radical cation compared with its α-dideuterated counterpart. A mechanism is suggested in which a fast OH deprotonation leads to a radical zwitterion which then undergoes a rate-determining 1,2-H shift, coupled to a side-chain-to-ring intramol. electron transfer (ET) step. This concept also attributes an important role to the energy barrier for this ET, which should depend on the stability of the pos. charge in the ring and, hence, on the number and position of methoxy groups. On a similar exptl. basis, the same mechanism is suggested for 2,5-(MeO)2C6H3CH2OH·+ as for 3,4-(MeO)2C6H3CH2OH·+, in which some contribution from direct C-H deprotonation (carbon acidity) is possible. In fact, the latter process dominates the decay of the trimethoxylated system 2,4,5-(MeO)3C6H2CH2-OH·+, which, accordingly, reacts with OH– at the same rate as that of its Me ether. Thus, a shift from oxygen to carbon acidity is observed as the pos. charge is increasingly stabilized in the ring; this is attributed to a corresponding increase in the energy barrier for the intramol. ET. When R = tBu, the OH–-promoted decay of the radical cation ArCH(OH)R·+ leads to products of C-C bond cleavage. With both Ar = 3,4- and 2,5-dimethoxyphenyl the reactivity is three orders of magnitude higher than that of the corresponding cumyl alc. radical cations; this suggests a mechanism in which a key role is played by the oxygen acidity as well as by the strength of the scissile C-C bond: a radical zwitterion is formed which undergoes a rate-determining C-C bond cleavage, coupled with the intramol. ET. Finally, oxygen acidity also determines the reactivity of the radical cations of 2-(3,4-dimethoxyphenyl)ethanol and 3-(3,4-dimethoxyphenyl)propanol. In the former the decay involves C-C bond cleavage, in the latter it leads to 3-(3,4-dimethoxyphenyl)propanal. In both cases no products of C-H deprotonation were observed Possible mechanisms, again involving the initial formation of a radical zwitterion, are discussed. In the experiment, the researchers used many compounds, for example, 3-(3,4-Dimethoxyphenyl)propan-1-ol (cas: 3929-47-3Recommanded Product: 3-(3,4-Dimethoxyphenyl)propan-1-ol).
3-(3,4-Dimethoxyphenyl)propan-1-ol (cas: 3929-47-3) belongs to ethers. Of all the functional groups, ethers are the least reactive ones. Ether bonds are quite stable towards bases, oxidizing agents and reducing agents. But on the other hand, ethers undergo cleavage by reaction with acids. At room temperature, ethers are pleasant-smelling colourless liquids. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil.Recommanded Product: 3-(3,4-Dimethoxyphenyl)propan-1-ol
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem