Lithium Cuprate Coupling Reactions: Evaluation of Computational Methods for Determination of the Reaction Mechanisms

Pratt, Lawrence M.; Voit, Stewart L; Khanh, Binh; Nguyen, BichLien H.

doi:10.1021/jp100076d

Cited by 12 publications

(12 citation statements)

References 35 publications

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“…at the MP2 and CCSD(T) levels of theory. The results, reported in the Supporting Information, confirmed the reliability of the adopted hybrid DFT scheme, in line with current literature studies 28. High‐temperature effects on the [Cu(hfa)(TMEDA)] + and [Cu(TMEDA‐(H)] +.…”

Section: Experimental and Computational Sectionsupporting

confidence: 88%

Lectin histochemical studies on the olfactory epithelium and vomeronasal organ in the Japanese striped snake, Elaphe quadrivirgata

Kondoh

Yamamoto

Nakamuta

et al. 2010

Journal of Morphology

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The olfactory epithelium and the vomeronasal organ of the Japanese striped snake were examined by lectin histochemistry. Of the 21 lectins used in the study, all lectins except succinylated-wheat germ agglutinin (s-WGA) showed similar binding patterns in the vomeronasal receptor cells and the olfactory receptor cells with varying intensities. The binding patterns of s-WGA varied among individuals in the vomeronasal and olfactory receptor cells, respectively. Four lectins, Bandeiraea simplicifolia lectin-II (BSL-II), Dolichos biflorus agglutinin (DBA), Sophora japonica agglutinin (SJA), and Erythrina cristagalli lectin (ECL) stained secretory granules and the organelles in the olfactory supporting cells and did not stain them in the vomeronasal supporting cells. These results suggest that the glycoconjugate moieties are similar in the vomeronasal and olfactory receptor cells of the Japanese striped snake.

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Section: Experimental and Computational Sectionsupporting

confidence: 88%

Lectin histochemical studies on the olfactory epithelium and vomeronasal organ in the Japanese striped snake, Elaphe quadrivirgata

Kondoh

Yamamoto

Nakamuta

et al. 2010

Journal of Morphology

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“…We note that previous theoretical calculations of the reactions of [CH 3 CuCH 3 ]and [CH 3 AgCH 3 ]with CH 3 I have been carried out at the MP2/6-31++G(d,p) level of theory, 8b while the reaction of [CH 3 CuCH 3 ]with methyl and vinyl chloride has also been studied at the B3LYP/6-31+G(d) level of theory. 25 Slight differences in the mechanisms of Path B were observed from these two studies. At the MP2 level, the reaction is a one step process proceeding via one transition state, while at the B3LYP level, reaction proceeds via two steps involving an oxidative addition transition state and a reductive elimination transition state.…”

Section: Results and Discussion (1) Gas Phase Formation Of Dimethylau...mentioning

confidence: 90%

Gas phase synthesis and reactivity of dimethylaurate

Rijs¹,

Sanvido²,

Khairallah³

et al. 2010

Dalton Trans.

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A combination of multistage mass spectrometry experiments and DFT calculations were used to examine the synthesis and reactivity of dimethylaurate. Collision induced dissociation (CID) of [(CH(3)CO(2))(4)Au](-) proceeded via reductive elimination of acetylperoxide to yield the diacetate [CH(3)CO(2)AuO(2)CCH(3)](-), which in turn underwent sequential CID decarboxylation reactions to yield the organoaurates [CH(3)CO(2)AuCH(3)](-) and [CH(3)AuCH(3)](-). The unimolecular chemistry of the dimethylaurate proceeds via a combination of bond homolysis to yield the methyl aurate radical anion [CH(3)Au] (-) as well as formation of the gold dihydride [HAuH](-). DFT calculations reveal that the latter anion is formed via a 1,2-dyotropic rearrangement to yield the isomer [CH(3)CH(2)AuH](-), followed by a beta-hydride elimination reaction. Ion-molecule reactions of [CH(3)AuCH(3)](-) with methyl iodide did not yield any products even at relatively high concentrations of the neutral substrate and longer reaction times, indicating a reaction efficiency of less than 1 in 20 000 collisions. DFT calculations were carried out on two different potential energy surfaces (PES) for the reaction of [CH(3)AuCH(3)](-) with CH(3)I: (i) an S(N)2 mechanism proceeding via a side-on transition state; and (ii) a stepwise mechanism proceeding via oxidative addition followed by reductive elimination. Both pathways have significant endothermic barriers, consistent with the lack of C-C bond coupling products being formed in the experiments. Finally, the reactivity of [CH(3)AuCH(3)](-) is compared to the previously studied [CH(3)AgCH(3)](-) and [CH(3)CuCH(3)](-), as well as condensed phase studies on dimethylaurate salts.

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“…The overall mechanism is illustrated in Scheme 3. We have previously shown that the cuprate coupling reaction mechanism is highly dependent on the aggregation state, 13 which is, in turn, dependent on solvation and other factors.…”

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confidence: 99%

Nickel-Catalyzed Alkyl Coupling Reactions: Evaluation of Computational Methods

et al. 2011

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The B3LYP, M06, M06L, M062X, MPW1K, and PBE1PBE DFT methods were evaluated for modeling nickel-catalyzed coupling reactions. The reaction consists of a nucleophilic attack by a carbanion equivalent on the nickel complex, S(N)2 attack by the anionic nickel complex on an alkyl halide, and reductive elimination of the coupled alkane product, regenerating the nickel catalyst. On the basis of CCSD(T)//DFT single-point energies, the B3LYP, M06, and PBE1PBE functionals were judged to generate the best ground state geometries. M06 energies are generally comparable or superior to B3LYP and PBE1PBE energies for transition state calculations. The MP2 and CCSD methods were also evaluated for single-point energies at the M06 geometries. The rate-determining step of this reaction was found to be nucleophilic attack of a L(2)NiR anion on the alkyl halide.

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Lithium Cuprate Coupling Reactions: Evaluation of Computational Methods for Determination of the Reaction Mechanisms

Cited by 12 publications

References 35 publications

Lectin histochemical studies on the olfactory epithelium and vomeronasal organ in the Japanese striped snake, Elaphe quadrivirgata

Lectin histochemical studies on the olfactory epithelium and vomeronasal organ in the Japanese striped snake, Elaphe quadrivirgata

Gas phase synthesis and reactivity of dimethylaurate

Nickel-Catalyzed Alkyl Coupling Reactions: Evaluation of Computational Methods

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