- Copper-Catalyzed Modular Amino Oxygenation of Alkenes: Access to Diverse 1,2-Amino Oxygen-Containing Skeletons
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Copper-catalyzed alkene amino oxygenation reactions using O-acylhydroxylamines have been achieved for a rapid and modular access to diverse 1,2-amino oxygen-containing molecules. This transformation is applicable to the use of alcohols, carbonyls, oximes, and thio-carboxylic acids as nucleophiles on both terminal and internal alkenes. Mild reaction conditions tolerate a wide range of functional groups, including ether, ester, amide, carbamate, and halide. The reaction protocol allows for starting with free amines as the precursor of O-benzoylhydroxylamines to eliminate their isolation and purification, contributing to broader synthetic utilities. Mechanistic investigations reveal the amino oxygenation reactions may involve distinct pathways, depending on different oxygen nucleophiles.
- Hemric, Brett N.,Chen, Andy W.,Wang, Qiu
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supporting information
p. 1468 - 1488
(2019/01/25)
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- Copper-Catalyzed Amino Lactonization and Amino Oxygenation of Alkenes Using O-Benzoylhydroxylamines
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A copper-catalyzed amino lactonization of unsaturated carboxylic acids has been achieved as well as the analogous intermolecular three-component amino oxygenation of olefins. The transformation features mild conditions and a remarkably broad substrate sco
- Hemric, Brett N.,Shen, Kun,Wang, Qiu
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supporting information
p. 5813 - 5816
(2016/06/09)
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- Rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes with terminal alkenes
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A rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes with terminal alkenes to afford 1,2-disubstituted alkenes with good regio- and E-selectivity is developed. This reaction employs readily available aromatic aldehydes as the aryl electrophile counterpart and relies on selected acyl chloride as the crucial additive to activate the rhodium catalyst precursor.
- Kang, Lei,Zhang, Feng,Ding, Lin-Ting,Yang, Luo
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p. 100452 - 100456
(2015/12/09)
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- Base-catalyzed ring openings of benzocyclobutenones and -ols
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The base-catalyzed ring opening of a number of isomeric E- and Z-benzylidenebenzocyclobutenones and -ols has been studied in both protic and aprotic solvents.Cleavage of the C1-C2 bond results in the formation of stilbenes with mainly, and at times exclusively, retained stereochemistry.For the alcohols, these results point to an oxyanion-induced carbon-carbon bond cleavage leading to a vinyl anion that is protonated with retention of configuration in the protic solvents rather than to an electrocyclic ring opening to an alkoxy o-quinodimethane.Reaction of the Z isomer of benzylidenebenzocyclobutenol with methyllithium in THF at 20 deg C causes isomerization to the E isomer, cleavage of the C1-C2 bond, and recyclization of the resultant isomerized vinyl anion. - Key words: benzylidenebenzocyclobutenones, base-catalyzed ring opening; benzylidenebenzocyclobutenols, base-catalyzed ring opening.
- Bradley, J. C.,Durst, T.
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p. 1660 - 1665
(2007/10/02)
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- Z-E photoisomerization of benzylidenebenzocyclobutenones via ketene- allene intermediates. A laser flash photolysis study
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Benzylidenebenzocyclobutenones I-E and I-Z undergo photoinduced isomerization via the intermediacy of ketene-allene II which in acetonitrile has a lifetime of ~26 μs and can be trapped with water and methanol. Trapping by the latter occurs with a rate constant of 1.2 x 104 M-1 s-1 and leads to the expected ester. In addition to Z = E isomerization, product studies reveal the formation of dimeric products in very low quantum yields.
- Boch,Bradley,Durst,Scaiano
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- Analysis of the 13C and 1H Spectra of Mixtures of Benzylidene Derivatives
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The 1H and 13C NMR spectra of methyl (E)-2,3-diphenylprop-2-enoate and methyl (E)-2-(2-phenylethenyl)benzoate resulting from the electrocyclic ring opening of benzocyclobutenone starting materials have been assigned.A combination of direct detection 2D NMR techniques, COSY, HETCOR, and FLOCK, provided the assignments of the 1H and 13C resonances. - Keywords: NMR 1H NMR 13C NMR Benzylidene derivatives
- Bradley, J. C.,Williams, A. J.
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p. 496 - 498
(2007/10/02)
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- Transmission of Polar Effects. Part 21. Alkaline Hydrolysis of the 2'- and 4'-substituted 2-Methoxycarbonyldiphenylacetylenes and (Z)-2'- and -4'- Substituted 2-Methoxycarbonylstilbenes and the Ionisation and Esterification, with Diazodiphenylmethane of t
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The rate coefficients for the alkaline hydrolysis of a series of 2'- and 4'-substituted 2-methoxycarbonyldiphenylacetylenes and (Z)-2-methoxycarbonylstilbenes have been determined in 70percent (v/v) dimethyl sulphoxide-water at both 30.0 and 50.0 deg C an
- Bowden, Keith,Ghadir, Khalaf D. F.
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p. 1333 - 1338
(2007/10/02)
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