20944-85-8Relevant articles and documents
A novel photorearrangement of aryl naphthylmethyl ethers. Formation of cyclohexa-2,4-dienone derivatives
Yoshimi, Yasuharu,Sugimoto, Akira,Maeda, Hajime,Mizuno, Kazuhiko
, p. 4683 - 4686 (1998)
Irradiation of a benzene solution containing 1-methoxycarbonyl-2- naphthylmethyl 2,6-dimethyl substituted phenyl ethers (1a,b) afforded cyclohexa-2,4-dienone derivatives (2a,b) as initial rearranged products via C-O bond cleavage and meta substituted phenols (3a,b) which were formed by subsequent photorearrangement of 2a,b.
Intramolecular photocycloaddition reactions of 2- and 4-(5-arylpent-4-enyl)-1-cyanonaphthalenes
Maeda, Hajime,Enya, Kouhei,Negoro, Naoki,Mizuno, Kazuhiko
, p. 173 - 184 (2019/02/15)
Photoreactions of 1-cyanonaphthalene derivatives containing 5-arylpent-4-enyl groups at C-2 or C-4 of the naphthalene ring were investigated. Photoreactions of C-2 derivatives in benzene or CH3CN generated intramolecular [2 + 2] and [3 + 2] photocycloadducts. Substances bearing electron-rich and electron-poor phenyl groups produced respective [2 + 2] and [3 + 2] photocycloadducts preferentially. In contrast, photoreactions of C-4 linked 1-cyanonaphthalenes produced intramolecular [4 + 2] photocycloadducts as main products along with stereoisomers of tricyclic compounds as minor products. The formation of [4 + 2] photocycloadducts was promoted by using benzophenone or Michler's ketone triplet photosensitization, and quenched by O2 or ferrocene. Intramolecular singlet exciplexes, which serve as important intermediates in the mechanistic pathways for these reactions, governed the site-selectivities in photoreactions of both of the 2- and 4-(5-arylpent-4-enyl)-1-cyanonaphthalenes. In addition, [4 + 2] photocycloadducts were observed to undergo di-π-methane rearrangement under irradiation conditions to produce angular triquinane derivatives.
Preparation method of aromatics methylation
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Paragraph 0136; 0137; 0138, (2019/11/20)
The invention relates to the technical field of organic synthesis or pharmaceutical chemistry, in particular to a preparation method of aromatics methylation. Under inert gas protection, a substrate A, a methylation reagent B and a termination agent C are used as starting materials, under the action of a catalyst D, a ligand E, a norborneene derivative G and a base F, the starting materials are subjected to a stirring reaction in an organic solvent H at 30-140 DEG C, and after the reaction, a reaction mixture is sucked and filtered, concentrated and purified to prepare a product of aromatics methylation shown as any formula of a formual I, a formual II and a formual III (please see the specifications for the formual I, the formual II and the formual III). According to the preparation method, related main raw materials are aryl iodide, trimethyl phosphate, methyl sulfonate, deuterated methyl ester sulfoacid, olefin, alkyne, an aryl boron compound, cyanide, bis(pinacolato)diboron and a proton source, the raw materials can be used as a commercial reagent without special treatment, the cost is low, and the variety is great. According to the method, aromatics methylation products can beprepared in large quantities (grams), and a good foundation is laid for industrial production.
Modular Dual-Tasked C-H Methylation via the Catellani Strategy
Gao, Qianwen,Shang, Yong,Song, Fuzhen,Ye, Jinxiang,Liu, Ze-Shui,Li, Lisha,Cheng, Hong-Gang,Zhou, Qianghui
supporting information, p. 15986 - 15993 (2019/10/11)
We report a dual-tasked methylation that is based on cooperative palladium/norbornene catalysis. Readily available (hetero)aryl halides (39 iodides and 4 bromides) and inexpensive MeOTs or trimethylphosphate are utilized as the substrates and methylating reagent, respectively. Six types of "ipso" terminations can modularly couple with this "ortho" C-H methylation to constitute a versatile methylation toolbox for preparing diversified methylated arenes. This toolbox features inexpensive methyl sources, excellent functional-group tolerance, simple reaction procedures, and scalability. Importantly, it can be uneventfully extended to isotope-labeled methylation by switching to the corresponding reagents CD3OTs or 13CH3OTs. Moreover, this toolbox can be applied to late-stage modification of biorelevant substrates with complete stereoretention. We believe these salient and practical features of our dual-tasked methylation toolbox will be welcomed by academic and industrial researchers.
Synthesis of pentacyclic compounds via intramolecular [3 + 2] photocycloaddition of cycloalkene linked naphthalenes
Maeda, Hajime,Uesugi, Tomoya,Fujimoto, Yasufumi,Mukae, Hirofumi,Mizuno, Kazuhiko
, p. 198 - 206 (2017/02/10)
Intramolecular photocycloaddition reactions of cycloalkene linked naphthalenes lead to formation of pentacyclic compounds in a high yielding and stereoselective manner. Intramolecular [2 + 2] cycloadducts are formed initially in photoreactions of cycloalkene linked 1-cyanonaphthalenes. The initially formed intramolecular [2 + 2] cycloadducts absorb light at wavelengths used to promote the photochemical reactions and, as a result, they undergo efficient photocycloreversion to regenerate the starting substrates. In a less efficient competing process, the cycloalkene linked 1-cyanonaphthalenes react to form [3 + 2] intramolecular photoadducts, which do not absorb incident light under the conditions used. Consequently, these photoadducts become the major products in these processes. The relative configuration of the major diastereomers of the pentacyclic products formed from photoreactions of cyclopentene linked naphthalenes (cis-cis) differ from those (cis-trans) arising from the cyclooctene linked substrates. The results of theoretical calculations, which show that steric factors govern the preferred facial mode of intramolecular addition, are in good agreement with the stereochemical course of these photoreactions.
Intramolecular Photocycloaddition Reactions of Arylcyclopropane Tethered 1-Cyanonaphthalenes
Maeda, Hajime,Matsuda, Shoji,Mizuno, Kazuhiko
, p. 8544 - 8551 (2016/09/28)
Intramolecular photocycloaddition reactions of 1-cyanonaphthalenes bearing an arylcyclopropane containing side chain were investigated. Photoreactions of members of this family in which the arylcyclopropane moiety is bonded at the 2-position of the 1-cyanonaphthalene ring produce head-to-head and head-to-tail 1,2-[3+2] photocycloadducts. On the other hand, substances in this family containing an arylcyclopropane side chain linked to the 4-position of the cyanoarene ring undergo photoreactions to form [4+3] photocycloadducts along with novel nine-membered ring products, which are produced by photochemically induced 10 conrotatory ring opening of the initially formed intramolecular [3+2] cycloadducts. The results of solvent effects and fluorescence investigations along with those focusing on corresponding intermolecular photoreactions demonstrate that the photocycloadducts are formed predominantly through an intramolecular exciplex mechanism and that a photoinduced intramolecular electron transfer pathway via zwitterionic biradicals might be partly responsible for the process when CH3CN is the solvent.
Acetonitrile as a cyanating reagent: Cu-catalyzed cyanation of arenes
Zhu, Yamin,Zhao, Mengdi,Lu, Wenkui,Li, Linyi,Shen, Zengming
supporting information, p. 2602 - 2605 (2015/06/16)
A novel approach to the Cu-catalyzed cyanation of simple arenes using acetonitrile as an attractive cyano source has been documented. The C-H functionalization of arenes without directing groups involves a sequential iodination/cyanation to give the desired aromatic nitriles in good yields. A highly efficient Cu/TEMPO system for acetonitrile C-CN bond cleavage has been discovered. TEMPO is used as a cheap oxidant and enables the reaction to be catalytic in copper. Moreover, TEMPOCH2CN 6 has been identified as the active cyanating agent and shows high reactivity for forming the -CN moiety.
Facile one-pot transformation of arenes into aromatic nitriles under metal-cyanide-free conditions
Tamura, Toshiyuki,Moriyama, Katsuhiko,Togo, Hideo
, p. 2023 - 2029 (2015/03/18)
Electron-rich arenes bearing methyl or methoxy groups on the aromatic ring were treated with dichloromethyl methyl ether and ZnBr2, and then with molecular iodine and aq. ammonia to give the corresponding aromatic nitriles in good yields. Using this method, febuxostat was efficiently prepared from 4-bromophenol in four steps. The method can be used for the preparation of aromatic nitriles from arenes in one pot under metal-cyanide-free conditions. Various electron-rich arenes could be effectively converted into the corresponding aromatic nitriles in good yields, by treatment with ZnBr2 and dichloromethyl methyl ether, followed by reaction with molecular iodine and aq. ammonia.
Catalytic cyanation of aryl iodides using DMF and ammonium bicarbonate as the combined source of cyanide: A dual role of copper catalysts
Pawar, Amit B.,Chang, Sukbok
supporting information, p. 448 - 450 (2014/01/06)
Cu(ii)-catalyzed cyanation of aryl iodides has been developed using DMF and ammonium bicarbonate as the combined source of cyanide. It is assumed that copper is involved both in the generation of CN units from DMF-ammonia and in the cyanation of aryl halides. A range of electron-rich and fused (hetero)aryl iodides underwent cyanation resulting in moderate to good yields.
Iron(II)-catalyzed direct cyanation of arenes with aryl(cyano)iodonium triflates
Shu, Zhibin,Ji, Wenzhi,Wang, Xi,Zhou, Yujing,Zhang, Yan,Wang, Jianbo
supporting information, p. 2186 - 2189 (2014/03/21)
A direct oxidative cyanation of arenes under FeII catalysis with 3,5-di(trifluoromethyl)phenyl(cyano)iodonium triflate (DFCT) as the cyanating agent has been developed. The reaction is applicable to wide range of aromatic substrates, including polycyclic structures and heteroaromatic compounds. Copyright
