- Electrophilic Substitution in Naphthalenes: Cyclisation of Naphthylbutanols to Tetrahydrophenanthrene
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Both 4-(1-naphthyl)butanol and 4-(2-naphthyl)butanol cyclised in refluxing boron trifluoride-ether to give 1,2,3,4-tetrahydrophenanthrene.By use of the corresponding 1,1-dideuteriobutanol derivatives and analysis of the products by 220 MHz 1H n.m.r. spectroscopy it has been demonstrated that the 1-naphthylbutanol cyclises by two distinct pathways, (a) by direct attack (84percent) at the 2-position, and (b) by ipso-attack (16percent) at the 1-position of the naphthalene nucleus, followed by rearrangement.The 2-naphthylbutanol cyclises exclusively by direct substitution at the 1-position.With 4-(4-methoxy-1-naphthyl)-1,1-dideuteriobutanol on the other hand the proportion of ipso-substitution rises to 71 percent as shown by the 360 MHz 1H n.m.r. spectra of the resulting mixture of tetrahydrophenanthrenes.
- Jackson, Anthony H.,Shannon, Patrick V. R.,Taylor, Paul W.
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- Transition Metal-Free Alkyne-Aldehyde Reductive C?C Coupling trough Cascade Borylation/Olefin Isomerization
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A direct approach to γ-keto esters through cascade alkyne-aldehyde reductive C?C coupling of propargyl esters and aromatic aldehydes under transition-metal-free (TM-free) fashion was developed. Compared with multistep processes, this procedure provides a
- Khan, Imran,Luo, Zhibin,Xu, Yin,Xie, Jimin,Zhu, Weihua,Liu, Bin
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- Photoredox-Catalyzed Isomerization of Highly Substituted Allylic Alcohols by C?H Bond Activation
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Photoredox-catalyzed isomerization of γ-carbonyl-substituted allylic alcohols to their corresponding carbonyl compounds was achieved for the first time by C?H bond activation. This catalytic redox-neutral process resulted in the synthesis of 1,4-dicarbonyl compounds. Notably, allylic alcohols bearing tetrasubstituted olefins can also be transformed into their corresponding carbonyl compounds. Density functional theory calculations show that the carbonyl group at the γ-position of allylic alcohols are beneficial to the formation of their corresponding allylic alcohol radicals with high vertical electron affinity, which contributes to the completion of the photoredox catalytic cycle.
- Guo, Kai,Huang, Jun,Li, Anding,Li, Yuanhe,Yang, Zhen,Zhang, Zhongchao
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supporting information
p. 11660 - 11668
(2020/05/25)
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- Nickel-Catalyzed Deaminative Acylation of Activated Aliphatic Amines with Aromatic Amides via C-N Bond Activation
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Deaminative functionalization of aliphatic primary amines has great synthetic utility. Herein, we describe a Ni-catalyzed reductive deaminative cross-electrophile coupling reaction between Katritzky salts and aromatic amides. This work provides examples of the synthesis of various ketones from alkylpyridinium salts, including both primary and secondary alkylamines. Given its mild reaction conditions and high functional group tolerance, this cross-coupling strategy is expected to be useful for late-stage functionalization of complex compounds.
- Yu, Chu-Guo,Matsuo, Yutaka
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p. 950 - 955
(2020/02/15)
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- Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters to synthesize γ-ketone esters
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This work concerns the Mg(OMe)2 promoted allylic isomerization of γ-hydroxy-α,β-alkenoic esters with TMEDA as an additive. The isomerization proceeded under mild conditions and afforded γ-keto esters in high yield (up to 96%) within 2 h. Both (Z)- and (E)-γ-hydroxy-α,β-alkenoic esters were tolerated under the reaction conditions. This transformation involves the in situ formation of a dienolate intermediate from the easily accessible γ-hydroxy-α,β-alkenoic ester. The in situ generated dienolate can react with benzaldehyde and undergo a practical, useful tandem allylic isomerization-Aldol reaction to afford more functionalized compounds.
- Lai, Luhao,Li, A-Ni,Zhou, Jiawei,Guo, Yarong,Lin, Li,Chen, Wei,Wang, Rui
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p. 2185 - 2190
(2017/03/17)
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- Intermolecular hydroacylation of acrylate esters: A new route to 1,4-dicarbonyls
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1,4-Dicarbonyl compounds can be prepared using a Rh(I) mediated hydroacylation reaction between (2-aminopicolyl)imines and acrylate esters followed by acid hydrolysis.
- Willis,Sapmaz
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p. 2558 - 2559
(2007/10/03)
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- Syntheses and antiinflammatory activity of some 6-aryl-2,3,4,5-tetrahydro-3-pyridazinones
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6-Aryl-2, 3, 4, 5-tetrahydro-3-pyridazinones (2c-22c) are obtained by dehydrocyclisation of various hydrazides formed by the reaction of appropriate methyl β-aroylpropionate and hydrazine hydrate in the presence of anhydrous sodium acetate. They show promising antiinflammatory activity during their evaluation by carrageenin induced paw edema test in rats.
- Khan,Siddiqui
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p. 614 - 619
(2007/10/03)
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