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As an advance in hydrofunctionalization, we herein report that alcohols add to 1,3-dienes with high regio- and enantioselectivity. Using Ni-DuPhos, we access enantioenriched allylic ethers. Through the choice of solvent-free conditions, we control the reversibility of C-O bond formation. This work showcases a rare example of methanol as a reagent in asymmetric synthesis.

We report the first enantioselective addition of pyrazoles to 1,3-dienes. Secondary and tertiary allylic pyrazoles can be generated with excellent regioselectivity. Mechanistic studies support a pathway distinct from previous hydroaminations: a Pd0 -catalyzed ligand-to-ligand hydrogen transfer (LLHT). This hydroamination tolerates a range of functional groups and advances the field of diene hydrofunctionalization.

C16H12ClFO5, monclinic, P21/c (no. 14), a = 14.7536(6) Å, b = 7.8281(3) Å, c = 14.0501(7) Å, β = 111.174(5)° $111.174(5){}^{\circ}$ , V = 1513.13(12) Å3, Z = 4, R gt(F) = 0.0367, wR ref(F 2) = 0.0865, T = 296(2) K.

In this Article, we expand upon the catalytic hydrothiolation of 1,3-dienes to afford either allylic or homoallylic sulfides with high regiocontrol. Mechanistic studies support a pathway in which regioselectivity is dictated by the choice of counterion associated with the Rh center. Non-coordinating counterions, such as SbF6-, allow for η4-diene coordination to Rh complexes and result in allylic sulfides. In contrast, coordinating counterions, such as Cl-, favor neutral Rh complexes in which the diene binds η2 to afford homoallylic sulfides. We propose mechanisms that rationalize a fractional dependence on thiol for the 1,2-Markovnikov hydrothiolation while accounting for an inverse dependence on thiol in the 3,4- anti-Markovnikov pathway. Through the hydrothiolation of an essential oil (β-farnesene), we achieve the first enantioselective synthesis of (-)-agelasidine A.

C9H11BrNiO8, monoclinic, P21/c (no. 14), a = 8.5077(16) Å, b = 6.7688(13) Å, c = 22.459(4) Å, β = 98.188(2)°, V = 1280.2(4) Å3, Z = 4, Rgt(F) = 0.0256, wRref(F2) = 0.0585, T = 296(2) K.

A novel approach was applied to synthesize B6O using CaB6 and B2O3 powders as reactants. CaB6 and B2O3 were reacted to generate B6O and CaB2O4 at 1573 K, and the by‐product CaB2O4 was removed by acid leaching. It was found that the samples prepared in this work were oxygen deficient (B6Ox, x ≈ .76–.77). The optimal molar ratio of CaB6 to B2O3 was determined to be 3:5, and excess B2O3 could not lead to a change in the value of oxygen occupancy. Scanning electron microscope images showed that regular holes similar to the morphologies of CaB6 particles were exhibited in the final samples, which could be explained by the diffusion of CaB6 during the reaction process. [ABSTRACT FROM AUTHOR]

We report a Rh-catalyzed hydrothiolation of 1,3-dienes, including petroleum feedstocks. Either secondary or tertiary allylic sulfides can be generated from the selective addition of a thiol to the more substituted double bond of a diene. The catalyst tolerates a wide range of functional groups, and the loading can be as low as 0.1 mol %.

We report a Rh-catalyzed hydroamination of 1,3-dienes to generate homoallylic amines. Our work showcases the first case of anti-Markovnikov selectivity in the intermolecular coupling of amines and 1,3-dienes. By tuning the ligand properties and Brønsted acid additive, we find that a combination of rac-BINAP and mandelic acid is critical for achieving anti-Markovnikov selectivity.

We communicate a strategy for the hydrofunctionalization of 1,3-dienes via Rh-hydride catalysis. Conjugated dienes are coupled to nucleophiles to demonstrate the feasibility of novel C-C, C-O, C-S, and C-N bond forming processes. In the presence of a chiral JoSPOphos ligand, hydroamination generates chiral allylic amines with high regio- and enantioselectivity. Tuning both the pKa and steric properties of an acid-additive is critical for enantiocontrol.

Unraveling the origin of Helmholtz capacitance is of paramount importance for understanding the interfacial structure and electrostatic potential distribution of electric double layers (EDL). In this work, we combined the methods of ab initio molecular dynamics and classical molecular dynamics and modeled electrified Cu(100)/electrolyte and graphene/electrolyte interfaces for comparison. It was proposed that the Helmholtz capacitance is composed of three parts connected in series: the usual solvent capacitance, water chemisorption induced capacitance, and Pauling repulsion caused gap capacitance. We found the Helmholtz capacitance of graphene is significantly lower than that of Cu(100), which was attributed to two intrinsic factors. One is that graphene has a wider gap layer at interface, and the other is that graphene is less active for water chemisorption. Finally, based on our findings, we provide suggestions for how to increase the EDL capacitance of graphene-based materials in future work, and we also suggest that the new understanding of the potential distribution across the Helmholtz layer may help explain some experimental phenomena of electrocatalysis. [ABSTRACT FROM AUTHOR]

Wind tunnel test results of the aerodynamic coefficients of sector-shape iced eight bundle conductors varying with wind attack angles are presented. Then, by means of the user-defined cable elements, the aerodynamic loads are applied on the cable elements of each sub-conductor through the finite element method (FEM). In addition, the galloping responses of sectorshape iced eight bundle conductors are discussed. Finally, galloping responses, including dynamic responses (natural modes and frequencies), galloping orbits, and amplitudes of typical sector-shape iced eight bundle conductor transmission lines in the cases of different span lengths, wind velocities, and angles of wind attack are studied, respectively. These results provide useful references for a theoretical basis for the study of galloping and the technique of anti-galloping in cold regions. Key words: sector-shape ice, eight bundle conductors, aerodynamic characteristics, wind tunnel test, finite element method (FEM). Les resultats des essais en soufflerie des coefficients aerodynamiques d'un groupe de huit conducteurs couverts de glace variant en fonction des angles d'attaque du vent sont presentes. Ensuite, au moyen des elements de cable definis par l'utilisateur, les charges aerodynamiques sont appliquees sur les elements de cable de chaque sous-conducteur par la methode des elements finis (FEM). De plus, la reponse galopante du groupe de huit conducteurs couverts de glace est discutee. Enfin, les reponses galopantes, y compris les reponses dynamiques (modes et frequences naturels), les orbites galopantes et les amplitudes des lignes de transmission types d'un groupe de huit conducteurs couverts de glace dans les cas de differentes longueurs de portee, vitesses du vent et angles d'attaque du vent sont etudies, respectivement. Ces resultats procurent des references utiles pour une base theorique dans le cadre de l'etude du galop et la technique anti- galop dans les regions froides. [Traduit par la Redaction] Mots-cles : glace formee sur un secteur, groupe de huit conducteurs, caracteristiques aerodynamiques, essai en soufflerie, methode des elements finis (FEM)., 1. Introduction Eight bundle conductor 1000 kV ultrahigh voltage (UHV) transmission lines have been launched to solve the imbalance problem between electric power supply and demand. Because of the complexity [...]