- Enantioselective iron/bisquinolyldiamine ligand‐catalyzed oxidative coupling reaction of 2‐naphthols
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An iron‐catalyzed asymmetric oxidative homo‐coupling of 2‐naphthols for the synthesis of 1,1′‐Bi‐2‐naphthol (BINOL) derivatives is reported. The coupling reaction provides enantioenriched BINOLs in good yields (up to 99%) and moderate enantioselectivities (up to 81:19 er) using an iron‐complex generated in situ from Fe(ClO4)2 and a bisquinolyldiamine ligand [(1R,2R)‐N1,N2‐di(quinolin‐8‐yl)cyclohexane‐1,2‐diamine, L1]. A number of ligands (L2–L8) and the analogs of L1, with various substituents and chiral backbones, were synthesized and examined in the oxidative coupling reactions.
- Liu, Wen-Bo,Usman, Muhammad,Wu, Lin-Yang
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- Enantioselective Ni-Catalyzed Electrochemical Synthesis of Biaryl Atropisomers
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A scalable enantioselective nickel-catalyzed electrochemical reductive homocoupling of aryl bromides has been developed, affording enantioenriched axially chiral biaryls in good yield under mild conditions using electricity as a reductant in an undivided cell. Common metal reductants such as Mn or Zn powder resulted in significantly lower yields in the absence of electric current under otherwise identical conditions, underscoring the enhanced reactivity provided by the combination of transition metal catalysis and electrochemistry.
- Chen, Song,Chen, Yue-Gang,Gao, Pei-Sen,Liu, Dong,Ma, Hong-Xing,Mei, Tian-Sheng,Qiu, Hui,Shuai, Bin,Wang, Yun-Zhao
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p. 9872 - 9878
(2020/06/27)
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- The Interrupted Pummerer Reaction in a Sulfoxide-Catalyzed Oxidative Coupling of 2-Naphthols
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A benzothiophene S-oxide catalyst, generated in situ by sulfur oxidation with H2O2, mediates the oxidative coupling of 2-naphthols. Key to the catalytic process is the capture and inversion of reactivity of a 2-naphthol partner, using an interrupted Pummerer reaction of an unusual benzothiophene S-oxide, followed by subsequent coupling with a second partner. The new catalytic manifold has been showcased in the synthesis of the bioactive natural products, (±)-nigerone and (±)-isonigerone. Although Pummerer reactions are used widely, their application in catalysis is rare, and our approach represents a new catalytic manifold for metal-free C?C bond formation.
- He, Zhen,Pulis, Alexander P.,Procter, David J.
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supporting information
p. 7813 - 7817
(2019/05/15)
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- De Novo Synthesis of Phenols and Naphthols through Oxidative Cycloaromatization of Dienynes
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In this work, a rhodium-catalyzed oxidative cycloaromatization of dienynes, which provides a highly straightforward and efficient way to access polysubstituted naphthols and phenols under mild conditions, is described. Challenged electron-withdrawing groups are well tolerated in this protocol, and late-stage phenyl ring formation is demonstrated.
- Rong, Ming-Guang,Qin, Tian-Zhu,Liu, Xin-Rui,Wang, Hong-Fa,Zi, Weiwei
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supporting information
p. 6289 - 6293
(2018/10/09)
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- Photocyclization and Photoaddition Reactions of Arylphenols via Intermediate Quinone Methides
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A series of five benzannelated derivatives of 2-phenylphenol were prepared, and their photochemistry was investigated. Two of these (3-phenyl-2-naphthol, 10, and 1-phenyl-2-naphthol, 11) were photoinert. For 2-(1-naphthyl)phenol (12) and 1-(1-naphthyl)-2-naphthol (13), ESPT took place to either the 2′-position or the 7′-position of the naphthalene ring to give quinone methides (QMs) that underwent either reverse proton transfer (RPT) or electrocyclic ring closure to give dihydrobenzoxanthenes. The intermediate QMs for 12 and 13 were detected and characterized by laser flash photolysis. For 2-(9-phenanthryl)phenol (14), ESPT took place either to the 5′-position to give a QM that underwent quantitative electrocyclic ring closure to give the corresponding benzoxanthene or to the 10′-position to give a QM that underwent RPT. If the solution contained methanol, the QM produced on ESPT to the 10′-position in 14 could be trapped as the photoaddition product. The compounds studied in this work demonstrate three possible reactions of QMs produced following ESPT to aromatic carbon atoms: (1) reverse proton transfer (RPT) to regenerate starting material; (2) addition of hydroxylic solvents to give the photoaddition product; and (3) electrocyclic ring closure to give benzoxanthene derivatives.
- Lukeman, Matthew,Simon, Hilary,Wan, Peter,Wang, Yu-Hsuan
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p. 11281 - 11293
(2015/12/01)
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- Regiospecific synthesis of novel cyclic nitrostyrenes and 3-substituted 2-nitronaphthalenes
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A two-step, practical, regiospecific, and readily scalable benzannulation protocol for the preparation of novel 3-alkyl- and 3-aryl-substituted 2-nitronaphthalenes is disclosed. Addition of a β-nitrostyrene or nitroalkene to a solution of freshly prepared lithiated o-tolualdehyde tert-butyl imine first leads to the formation of a nitronate, via rapid 1,4-addition, then an intramolecular aza-Henry reaction takes place to afford a six-membered carbocycle. Subsequent treatment of the reaction mixture with aqueous acid affords novel substituted cyclic nitrostyrenes that can be conveniently aromatized via a one-pot radical-induced bromination and elimination sequence to furnish the corresponding 3-alkyl- or 3-aryl-2-nitronaphthalenes in excellent yields. The straightforward syntheses of 2-aminonaphthalenes, substituted BINAMs, 2-naphthols as well as tricyclic fused 1,2,3-triazoles are also described. Georg Thieme Verlag Stuttgart. New York.
- Keene, Craig,Kuerti, Laszlo
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supporting information
p. 1719 - 1729
(2013/07/26)
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- Synthesis of chiral 1,3-disubstituted tetrahydroisoquinolines and their use in the asymmetric addition of diethylzinc to aldehydes
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The effects of modifications on three sites of 1-(1,2,3,4-tetrahydro- isoquinolin-1 -yl)-naphthalen-2-ol (THIQNOL) chiral ligands the asymmetric diethylzinc additions were examined. The studies showed that modifications at the nitrogen only reduce the eff
- MacLeod, Patricia D.,Reckling, Amy M.,Li, Chao-Jun
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experimental part
p. 1319 - 1337
(2010/10/20)
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- Studies on the chemistry of 2-(2-oxo-3-phenylpropyl)-benzaldehydes: Novel total synthesis of 3-phenylnaphthalen-2-ols and 2-hydroxy-3-phenyl-1,4- naphthoquinones
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We describe the first studies on the chemistry of 2-(2-oxo-3-phenylpropyl) benzaldehydes, which were converted into 3-benzylisochromen-1-ones via the corresponding 2-(2-oxo-3-phenylpropyl)benzoic acid. The 2-(2-oxo-3-phenylpropyl) benzaldehydes proved to be convenient starting materials for the synthesis of 3-phenyl-2-naphthols. Oxidation of the latter compounds resulted in a novel, efficient synthesis of 3-phenyl-1,2-naphthoquinones, which were efficiently transformed into 2-hydroxy-3-phenyl-1,4-naphthoquinones.
- Martínez, Ana,Fernández, Marcos,Estévez, Juan C.,Estévez, Ramón J.,Castedo, Luis
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p. 485 - 492
(2007/10/03)
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- Ruthenium-catalyzed cyclization of epoxide with a tethered alkyne: Formation of ketene intermediates via oxygen transfer from epoxides to terminal alkynes
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Treatment of (o-ethynyl)phenyl epoxides with TpRuPPh3(CH 3CN)2PF6 (10 mol %) in hot toluene (100 °C, 3-6 h) gave 2-naphthols or 1-alkylidene-2-indanones very selectively with isolated yields exceeding 72%, depen
- Madhushaw, Reniguntala J.,Lin, Ming-Yuan,Abu Sohel, Shariar Md.,Liu, Rai-Shung
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p. 6895 - 6899
(2007/10/03)
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- Rhodium-HMPT-catalyzed direct ortho arylation of phenols with aryl bromides
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Direct ortho arylation of phenols with aryl bromides catalyzed by a rhodium complex and hexamethylphosphorous triamide (HMPT) have been developed. A plausible reaction mechanism involving in situ generation of arylphosphites from phenols and HMPT, phosphorus-directed ortho metalation, and transesterification of the arylated arylphosphites with the substrate phenols is proposed.
- Oi, Shuichi,Watanabe, Shun-Ichiro,Fukita, Susumu,Inoue, Yoshio
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p. 8665 - 8668
(2007/10/03)
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- Recyclization of 3-Alkyl- and 1,3-Dialkylisoquinolinium Salts to Naphthylamines
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3-Methyl- and 3-benzylisoquinolinium salts undergo rearrangement to 2-alkylaminonaphthalenes under the influence of alcohol solutions of alkylamines.The rearrangement of 1,3-dimethyl- and 1-methyl-3-benzylisoquinolinium salts leads to both 1- and 2-alkylaminonaphthalenes with predominance of the former.
- Kost, A. N.,Terenin, V. I.,Yudin, L. G.,Sagitullin, R. S.
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p. 965 - 969
(2007/10/02)
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