Reactions of Palladium(II) with Organic Compounds. Part 5. Effect of Reaction Conditions upon Products of Oxidation of α-Methylstyrene

Norman, Richard O. C.,Thomas, C. Barry,Watson, Grenville

, p. 1099 - 1104 (1980)

The effects upon product distribution of varying the temperature, time of reaction, and reagent concentrations have been investigated in the oxidation of α-methylstyrene by palladium(II) acetate.Two reaction pathways have been identified.A ?-allylic organopalladium compound decomposes slowly in a process catalysed by excess of the alkene to give 2-phenylprop-2-enyl acetate.The second reaction leads to competitive formation of enolic acetates and oxidative dimers but the organopalladium species involved has not been unambiguously identified.The addition of sodium acetate to the reaction, contrary to earlier reports, has only a marginal effect upon the distribution of products.

Comparative Studies on the Addition Reactions of the Normant Reagent ("CH3MgBr" + CuBr) and the New Tetrahydrofuran-Soluble Magnesium Methylcuprates MgmCun(CH3)2m+n with Phenylacetylene

Ashby, E. C.,Smith, R. Scott,Goel, A. B.

, p. 5133 - 5139 (1981)

Reactions of phenylacetylene with the Normant reagent ("CH3MgBr" + CuBr) and the THF-soluble magnesium methyl cuprates MgmCun(CH3)2m+n obtained from the reaction of (CH3)2Mg with CuBr have been studied in detail.An attempt to determine the reactive species in Normant reagents was made by studying the rate of reaction of the Normant reagent with phenylacetylene compared to the rate observed with various magnesium methylcuprates.Cu4Mg(CH3)6 and Cu6Mg(CH3)8 have been shown to be the most probable candidates responsible for reactions involving the Normant reagent with alkynes.The effect of MgBr2 and LiBr on the reactivity and the product selectivity has also been studied.

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Georgiou et al.

, p. 253 (1974)

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Kampmeier,Fantazier

, p. 1959 (1966)

Organophotoredox-Catalyzed Decarboxylative C(sp3)-O Bond Formation

Shibutani, Shotaro,Kodo, Taiga,Takeda, Mitsutaka,Nagao, Kazunori,Tokunaga, Norihito,Sasaki, Yusuke,Ohmiya, Hirohisa

, p. 1211 - 1216 (2020)

This manuscript reports a visible-light-mediated organosulfide catalysis that enables the decarboxylative coupling between simple aliphatic alcohol and tertiary or secondary alkyl carboxylic acid-derived redox active esters to produce a C(sp3)-O-C(sp3) fragment. Results of the coupling using other heteroatom nucleophiles such as water, amides, and thiols are also described.

To Rebound or...Rebound? Evidence for the "alternative Rebound" mechanism in Ca'H Oxidations by the systems nonheme Mn Complex/H2O2/carboxylic acid

Ottenbacher, Roman V.,Bryliakova, Anna A.,Shashkov, Mikhail V.,Talsi, Evgenii P.,Bryliakov, Konstantin P.

, p. 5517 - 5524 (2021/05/31)

In this work, it has been shown that aliphatic Ca'H oxidations by bioinspired catalyst systems Mn aminopyridine complex/H2O2/carboxylic acid in acetonitrile afford predominantly a mixture of the corresponding alcohol and the ester. The alcohol/ester ratio is higher for catalysts bearing electron-donating groups at the aminopyridine core. Isotopic labeling studies witness that the oxygen atom of the alcohol originates from the H2O2molecule, while the ester oxygen comes exclusively from the acid. Oxidation of ethylbenzene in the presence of acetic acid affords enantiomerically enriched 1-phenylethanol and 1-phenyl acetate, with close enantioselectivities and the same sign of absolute chirality. Experimental data and density functional theory calculations provide evidence in favor of the rate-limiting benzylic H atom abstraction by the high-spin (S = 1) [LMnV(O)OAc]2+active species followed by competitive OH/OC(O)R rebound. This mechanism has been unprecedented for Ca'H oxidations catalyzed by bioinspired Mn complexes. The trends governing the alcohol/ester ratios have been rationalized in terms of steric properties of the catalyst, acid, and substrate. copy; 2021 American Chemical Society.

Iron-catalysed 1,2-aryl migration of tertiary azides

Wei, Kaijie,Yang, Tonghao,Chen, Qing,Liang, Siyu,Yu, Wei

supporting information, p. 11685 - 11688 (2020/10/19)

1,2-Aryl migration of α,α-diaryl tertiary azides was achieved by using the catalytic system of FeCl2/N-heterocyclic carbene (NHC) SIPr·HCl. The reaction generated aniline products in good yields after one-pot reduction of the migration-resultant imines.