- Catalytic Asymmetric Synthesis of Atropisomeric Quinolines through the Friedl?nder Reaction
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A phosphoric acid catalyzed atroposelective Friedl?nder reaction was developed in which acetylacetone and a variety of 2′-substituted 2-Aminobenzophenones were successfully employed to give optically active biaryl quinolines in good yields and with high enantioselectivities.
- Hu, Xingena,Jiang, Jun,Lan, Yunjun,Li, Juan,Li, Xinhua,Liu, Hongxin,Wan, Junlin,Xiao, Hong-Ping
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supporting information
p. 2198 - 2202
(2019/11/25)
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- Hf(OTf)4-Catalyzed highly diastereoselective synthesis of 1,3-disubstituted tetralin derivatives via benzylic C(sp3)-H bond functionalization
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We report a highly diastereoselective synthesis of 1,3-disubstituted tetralin derivatives via Lewis acid catalyzed benzylic C(sp3)-H bond functionalization. The employment of Hf(OTf)4 as an acid catalyst was crucial in the reaction,
- Yoshida, Taira,Mori, Keiji
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p. 4319 - 4322
(2017/04/21)
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- Construction of dibenzo-fused seven- to nine-membered carbocycles via Bronsted acid-promoted intramolecular Friedel - Crafts-type alkenylation
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Bronsted acid-promoted intramolecular hydroarylation of alkynylbenzenes carrying an arylalkyl group at the ortho-position leads to alkylidenedibenzo[a,d]cycloheptenes, -octenes and -nonenes in up to quantitative yield with complete regioselectivity. The scope and limitation of this reaction and application to the synthesis of tricyclic antidepressants are described.
- Otani, Takashi,Ueki, Kanako,Cho, Kinryo,Kanai, Kan,Tateno, Kotaro,Saito, Takao
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p. 7895 - 7898
(2015/05/13)
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- Multiple organolithium generation in the continuous flow synthesis of amitriptyline
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A continuous flow protocol for the preparation of the tricyclic antidepressant (TCA) amitriptyline is reported. The advantages of flow chemistry when handling organometallic agents as well as when performing reaction with gases are demonstrated. Continuous multilithiation combined with carboxylation and the Parham cyclization, a Grignard addition and thermolytic water elimination by inductive heating are key features of the multistep protocol. Copyright
- Kupracz, Lukas,Kirschning, Andreas
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supporting information
p. 3375 - 3380
(2013/12/04)
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- Iridium-catalyzed borylation of secondary benzylic C-H bonds directed by a hydrosilane
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Most functionalizations of C-H bonds by main-group reagents occur at aryl or methyl groups. We describe a highly regioselective borylation of secondary benzylic C-H bonds catalyzed by an iridium precursor and 3,4,7,8-tetramethyl-1, 10-phenanthroline as the ligand. The reaction is directed to the benzylic position by a hydrosilyl substituent. This hydrosilyl directing group is readily deprotected or transformed to other functional groups after the borylation reaction, providing access to a diverse set of secondary benzylboronate esters by C-H borylation chemistry.
- Cho, Seung Hwan,Hartwig, John F.
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supporting information
p. 8157 - 8160
(2013/07/05)
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- Potassium tert-butoxide promoted intramolecular arylation via a radical pathway
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Potassium tert-butoxide mediated intramolecular cyclization of aryl ethers, amines, and amides was efficiently performed under microwave irradiation to provide the corresponding products in high regioisomeric ratios. The reaction proceeds via single-electron transfer to initiate the formation of an aryl radical, followed by a kinetically favored 5-exo-trig and subsequent ring expansion.
- Roman, Daniela Sustac,Takahashi, Yoko,Charette, Andre B.
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supporting information; experimental part
p. 3242 - 3245
(2011/08/02)
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- Synthesis of unsymmetrically substituted biaryls via sequential lithiation of dibromobiaryls using integrated microflow systems
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A microflow system consisting of micromixers and microtube reactors provides an effective method for the introduction of two electrophiles onto dibromobiaryls. Selective monolithiation of dibromobiaryls, such as 2,2'-dibromobiphenyl, 4,4'-dibromobiphenyl, 2,7-dibromo-9,9-dioctylfluorene, 2,2'-dibromo-1,1'-binaphthyl, and 2,2'-dibromobibenzyl with 1 equiv of n-butyllithium followed by the reaction with electrophiles was achieved using a microflow system by virtue of fast micromixing and precise temperature control. Sequential introduction of two different electrophiles was achieved using an integrated microflow system composed of four micromixers and four microtube reactors to obtain unsymmetrically substituted biaryl compounds.
- Nagaki, Aiichiro,Takabayashi, Naofumi,Tomida, Yutaka,Yoshida, Jun-Ichi
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supporting information; experimental part
(2010/04/22)
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- Flash vacuum pyrolysis over magnesium. Part 1 - Pyrolysis of benzylic, other aryl/alkyl and aliphatic halides
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Flash vacuum pyrolysis over a bed of freshly sublimed magnesium on glass wool results in efficient coupling of benzyl halides to give the corresponding bibenzyls. Where an ortho halogen substituent is present further dehalogenation gives some dihydroanthracene and anthracene. Efficient coupling is also observed for halomethylnaphthalenes and halodiphenylmethanes while chlorotriphenylmethane gives 4,4′-bis(diphenylmethyl)biphenyl. By using α,α′-dihalo-o-xylenes, benzocyclobutenes are obtained in good yield, while the isomeric α,α′-dihalo-p-xylenes give a range of high thermal stability polymers by polymerisation of the initially formed p-xylylenes. Other haloalkylbenzenes undergo largely dehydrohalogenation where this is possible, in some cases resulting in cyclisation. Deoxygenation is also observed with haloalkyl phenyl ketones to give phenylalkynes as well as other products. With simple alkyl halides there is efficient elimination of HCl or HBr to give alkenes. For aliphatic dihalides this also occurs to give dienes but there is also cyclisation to give cycloalkanes and dehalogenation with hydrogen atom transfer to give alkenes in some cases. For 5-bromopent-1-ene the products are those expected from a radical pathway but for 6-bromohex-1-ene they are clearly not. For 2,2-dichloropropane and 1,1-dichloropropane elimination of HCl occurs but for 1,1-dichlorobutane, -pentane and -hexane partial hydrolysis followed by elimination of HCl gives E, E-, E,Z- and Z,Z- isomers of the dialk-1-enyl ethers and fully assigned 13C NMR data are presented for these. With 6-chlorohex-1-yne and 7-chlorohept-1-yne there is cyclisation to give methylenecycloalkanes and -cycloalkynes. The behaviour of 1,2-dibromocyclohexane and 1,2-dichlorocyclooctane under these conditions is also examined. Various pieces of evidence are presented that suggest that these processes do not involve generation of free gas-phase radicals but rather surface-adsorbed organometallic species.
- Aitken, R. Alan,Hodgson, Philip K.G.,Morrison, John J.,Oyewale, Adebayo O.
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p. 402 - 415
(2007/10/03)
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- Fungicides
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This invention relates to derivatives of acrylic acid useful as fungicides, to processes for preparing them, to fungicidal compositions containing them, and to methods of combating fungi, especially fungal infections in plants, using them.
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- Fungicides
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Compounds of formula: ψψ and stereoisomers thereof, wherein X, Y and Z, which may be the same or different, are hydrogen or halogen atoms, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted aryl, optionally substituted alkynyl, haloalkyl, alkoxy, haloalkoxy, optionally substituted aryloxy, optionally substituted arylalkoxy, optionally substituted acyloxy, optionally substituted amino, optionally substituted arylazo, acylamino, nitro, nitrile, -CO2R3, -CONR4R5, -COR6, -CR7=NR8, or -N=CR9R10 groups; or the groups X and Y, when they are in adjacent positions on the phenyl ring, may join to form a fused ring, either aromatic or aliphatic, optionally containing one or more heteroatoms; and R1, Ry, R3, R4, R5, R6, R7, R8, R9 and R10, which may be the same or different, are hydrogen atoms or alkyl, cycloalkyl, alkenyl, alkynyl, optionally substituted aryl, optionally substituted aralkyl, or cycloalkylalkyl groups; and metal complexes thereof.ψ
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