7175-89-5Relevant articles and documents
Elemental Sulfur-Promoted Synthesis of 4-Hydroxybenzophenones from p-Quinone Methides under Metal-Free Condition
Li, Jingping,Wang, Kunpeng,Wu, Jiayi,Zhang, Haoxiang,Chen, Yan,Liu, Qinglei,Xu, Junju,Yi, Weiyin
, (2022/05/20)
Conventional methods for the general and efficient synthesis of 4-hydroxybenzo- phenones are extremely underdeveloped and limited. We herein report a challenging metal-free protocol to rapidly construct 4-hydroxybenzophenones from para-quinone methides (p-QMs) in DMSO in the presence of KOH using the inexpensive and readily available elemental sulfur as redox reagent. As an unprecedented method, this simple but efficient approach has excellent site specificity, green sustainability, excellent atomic economy, and broad functional group compatibilities. Mechanistic studies show that the novel reaction proceeds through a radical pathway.
Oxygenation of tert-Butylphenols with an Unsaturated Side Chain
Nishinaga, Akira,Iwasaki, Hitoshi,Shimizu, Tadashi,Toyoda, Yasushi,Matsuura, Teru
, p. 2257 - 2266 (2007/10/02)
Base- and Co(Salpr)-promoted oxygenations of title compounds have been investigated with a view to obtaining further details concerning controlling factors in regioselective O2 incorporation into phenols.In the oxygenation of 4-alkenyl-2,6-di-tert-butyl- and 2-alkenyl-4,6-di-tert-butylphenols (1 and 12), the reactivity of the substrates and regioselectivity in the O2 incorporation may be interpreted in terms of electronic and steric effects of the alkenyl group as well as association effect of the countercation K+ on the transition-state 26 involving a charge transfer from the substrate anion to O2.With 4-alkynyl-2,6-di-tert-butylphenols (21), dioxygen was incorporated exclusively into the ortho position only when the phenolate anion was associated with K+.On the contrary, in the oxygenation of 1 and 12 with Co(Salpr), O2 was incorporated exclusively into the alkynyl side chain, regardless of the nature of the substituent, whereas with 21, O2 incorporation was distributed to both the ortho and the alkenyl side chain.The substituent-dependent regioselectivity in the oxygenation of phenols with Co(Salpr) is because the reactive phenolate-COIII species undergo homolysis to form phenoxy radical-CoII species reversibly, whose oxygenations compete with each other.When the oxygenation of the anionic species predominates, O2 is incorporated into the ortho position, whereas with the radical species the para and side chain oxydations predominate.
INVESTIGATION OF COMPOUNDS WITH JUVENILE ACTIVITY. XV. SYNTHESIS OF 2,6-DI-TERT-BUTYL-4-ACYLPHENOLS
Sergovskaya, N. L.,Kornienko, N. I.,Shekhter, O. V.,Tsizin, Yu. S.
, p. 1910 - 1913 (2007/10/02)
A series of 2,6-di-tert-butyl-4-acylphenols, which inhibit the development of the mosquito larva, were synthesized.These compounds were obtained either by acylation of 2,6-di-tert-butylphenol with the chlorides of benzoic or phenylacetic acids or by the reaction of 3,5-di-tert-butyl-4-hydroxyphenyl bromomethyl ketone with thiols or amines.Apart from the new compounds, the highly active larvicide benzyl 3,5-di tert-butyl-4-hydroxythiobenzoate, used as a standard for biological tests, was synthesized.
