- Cobalt-Catalyzed Desymmetric Isomerization of Exocyclic Olefins
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Chiral cyclic olefins, 1-methylcyclohexenes, are versatile building blocks for the synthesis of pharmaceuticals and natural products. Despite the prevalence of these structural motifs, the development of efficient synthetic methods remains an unmet challenge. Herein we report a novel desymmetric isomerization of exocyclic olefins using a series of newly designed chiral cobalt catalysts, which enables a straightforward construction of chiral 1-methylcyclohexenes with diversified functionalities. The synthetic utility of this methodology is highlighted by a concise and enantioselective synthesis of a natural product, β-bisabolene. The versatility of the reaction products is further demonstrated by multifarious derivatizations.
- Lan, Yu,Liu, Qiang,Liu, Shihan,Liu, Xufang,Rong, Xianle
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supporting information
p. 20633 - 20639
(2021/12/17)
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- The reaction of phenol with 1-methylcycloalkenes in the presence of phosphorus-containing zeolite y
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The results of cycloalkylation of phenol with 1-methylcyclopentene and 1-methylcyclohexene in the presence of phosphoric acid-impregnated zeolite are presented. Optimal conditions for the synthesis of 4(1-methylcycloalkyl)phenols were found. It was shown
- Rasulov,Azizov,Zeinalova,Azimova,Abasova,Rashidova
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p. 409 - 411
(2008/04/03)
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- Acidity effect in the regiochemical control of the alkylation of phenol with alkenes
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Treatment of 1:1 mixtures of phenol and linear alkenes in the presence of an acidic promoter in CHCl3 at room temperature results in ortho-regioselective monoalkylation producing sec-alkylphenols in 48-60% yield. In similar reactions, branched alkenes lead exclusively to the corresponding para-tert-alkylphenols in 80-85% yield. Addition of increasing amounts of potassium phenolate to the reacting system reduces the protic acidity and promotes ortho-regioselective tert-alkylation. These results are tentatively explained in terms of competition of 'H-bond-template' and 'charge-controlled' mechanisms.
- Sartori, Giovanni,Bigi, Franca,Maggi, Raimondo,Arienti, Attilio
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p. 257 - 260
(2007/10/03)
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- Reaction of phenol with alkyl- and alkenylcyclenes in the presence of catalyst KU-23
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An investigation has been made of the cycloalkylation of phenol by five- and six-membered alkyl- and alkenylcyclenes in the presence of cationite KU-23. The use of KU-23 makes it possible to produce products in yields of 90-95 wt.%, and here the displacem
- Sadykhov,Babikov,Yaskin,Sadykhov,Zeinalova,Shakhtakhtinskaya
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p. 155 - 165
(2007/10/03)
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- Conformational Dependence of 13C SCS in 1-Methyl-1-phenylcyclohexanes
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13C chemical shift data are reported for a series of para-substituted 1-methyl-1-phenylcyclohexanes at 22 and -100 deg C.The magnitudes of the SCS at alkyl and cycloalkyl carbon positions are discussed.The SCS at C-methyl and C-4 are significantly differe
- Cook, Michael J.,Nasri, Khalida A.
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p. 644 - 647
(2007/10/02)
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