1541-20-4Relevant articles and documents
Efficient photochemical oxygenation of cyclohexene with water as an oxygen donor sensitized by dimethoxy-coordinated tetraphenylporphyrinatoantimony(V)
Shiragami, Tsutomu,Kubomura, Kyouichi,Ishibashi, Daisuke,Inoue, Haruo
, p. 6311 - 6312 (1996)
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Addition of dihalocarbenes to corannulene. A fullerene-type reaction
Preda,Scott
, p. 9633 - 9637 (2000)
Dihalocarbenes (:CCl2, :CBr2, and :CI2) add preferentially to one of the radial double bonds of corannulene, rather than to the rim. These cyclopropanations strongly resemble the additions of dihalocarbenes to fullerenes, which likewise occur at 6:6-double bonds, destroy the cyclic conjugation in two adjacent benzene rings, and give 'closed' adducts. An explanation is offered for the abnormally high reactivity of the interior carbon atoms of corannulene. (C) 2000 Elsevier Science Ltd.
The Chemistry of 5-Oxodihydroisoxazoles. XIII. Reactions of the Imino Carbene Derived from Photolysis of Ethyl 5-Oxo-2-phenyl-2,5-dihydroisoxazole-4-carboxylate
Ang, Kiah H.,Prager, Rolf H.,Williams, Craig M.
, p. 567 - 576 (1995)
Photolysis of ethyl 5-oxo-2-phenyl-2,5-dihydroisoxazole-4-carboxylate at 300 nm in acetonitrile gives a carbene which is captured efficiently by bromide, chloride, acetate and cyanate, and less efficiently by iodide, thiocyanate, cyclohexene and tetrahydr
Photochemical Organocatalytic Benzylation of Allylic C–H Bonds
Le Saux, Emilien,Melchiorre, Paolo,Zanini, Margherita
supporting information, p. 1113 - 1118 (2022/02/05)
We report a radical-based organocatalytic method for the direct benzylation of allylic C–H bonds. The process uses nonfunctionalized allylic substrates and readily available benzyl radical precursors and is driven by visible light. Crucial was the identification of a dithiophosphoric acid that performs two distinct catalytic roles, sequentially acting as a catalytic donor for the formation of photoactive electron donor–acceptor (EDA) complexes and then as a hydrogen atom abstractor. By mastering these orthogonal radical generation paths, the organic catalyst enables the formation of benzylic and allylic radicals, respectively, to then govern their selective coupling. The protocol was also used to design a three-component radical process, which increased the synthetic potential of the chemistry.
Direct cross-coupling between alkenes and tetrahydrofuran with a platinum-loaded titanium oxide photocatalyst
Tyagi, Akanksha,Yamamoto, Akira,Yamamoto, Muneaki,Yoshida, Tomoko,Yoshida, Hisao
, p. 2546 - 2556 (2018/06/01)
A Pt-loaded TiO2 photocatalyst successfully catalyzed the direct cross-coupling between various alkenes and tetrahydrofuran (THF) without any additional oxidizing agent. The reaction between cyclohexene and THF gave three cross-coupling products, namely, 2-cyclohexyltetrahydrofuran (A), 2-(cyclohex-2-en-1-yl)tetrahydrofuran (B) and 2-(cyclohex-1-en-1-yl)tetrahydrofuran (C), along with gaseous hydrogen. The mechanistic study revealed that these products were formed through different individual mechanisms: successive addition of two radical species, a 2-tetrahydrofuranyl radical and a hydrogen radical, to the double bond of cyclohexene for A, coupling of a 3-cyclohexenyl radical and a 2-tetrahydrofuranyl radical for B, and 2-tetrahydrofuranyl radical addition and hydrogen radical elimination at the double bond of cyclohexene for C. Among these three mechanisms, those for B and C are dehydrogenative. In this photocatalytic reaction system, since the cyclohexene molecule has enough reactivity, due to the localized π electron density, the Pt nanoparticles loaded on the TiO2 function not as a metal catalyst but as an electron receiver to enhance the charge separation, although the dehydrogenative cross-coupling of benzene with THF requires Pd metal catalysis.
Cobalt-catalyzed oxidative esterification of allylic/benzylic C(sp3)–H bonds
Ren, Tian-Lu,Xu, Bao-Hua,Mahmood, Sajid,Sun, Ming-Xue,Zhang, Suo-Jiang
supporting information, p. 2943 - 2948 (2017/04/26)
A protocol for the cobalt-catalyzed oxidative esterification of allylic/benzylic C(sp3)–H bonds with carboxylic acids was developed in this work. Mechanistic studies revealed that C(sp3)–H bond activation in the hydrocarbon was the turnover-limiting step and the in-situ formed [Co(III)]Ot-Bu did not engage in hydrogen atom abstraction (HAA) of a C–H bond. This protocol was successfully incorporated into a synthetic pathway to β-damascenone that avoided the use of NBS.
