Solvent-free Sodium Research Articles

ChemInform Abstract: Solvent‐Free Multicomponent Assembling of Isatins, Malononitrile, and Dimedone: Fast and Efficient Way to Functionalized Spirooxindole System.

Solvent-free sodium acetate catalyzed multicomponent reaction of isatins, malononitrile, and dimedone initiated by grinding in mortar results in the fast and efficient formation of substituted spirooxindoles in 90–99 % yields. The developed solvent-free fast multicomponent approach to the substituted spirooxindoles—the pharmacologically perspective substances with spasmolytic, diuretic, anticoagulant, anticancer, and antianaphylactic activities—is beneficial from the viewpoint of diversity-oriented large-scale processes and represents fast efficient and environmentally benign solvent-free synthetic concept for multicomponent reactions strategy.

Solvent-free multicomponent assembling of isatins, malononitrile, and dimedone: fast and efficient way to functionalized spirooxindole system

Solvent-free sodium acetate catalyzed multicomponent reaction of isatins, malononitrile, and dimedone initiated by grinding in mortar results in the fast and efficient formation of substituted spirooxindoles in 90–99 % yields. The developed solvent-free fast multicomponent approach to the substituted spirooxindoles—the pharmacologically perspective substances with spasmolytic, diuretic, anticoagulant, anticancer, and antianaphylactic activities—is beneficial from the viewpoint of diversity-oriented large-scale processes and represents fast efficient and environmentally benign solvent-free synthetic concept for multicomponent reactions strategy.

Predicting the Sensitivity of Multiscale Coarse-Grained Models to their Underlying Fine-Grained Model Parameters.

The sensitivity of a coarse-grained (CG) force field to changes in the underlying fine-grained (FG) model from which it was derived provides modeling insight for improving transferability across interaction parameters, transferability across temperature, and the calculation of thermodynamic derivatives. Methods in the literature, such as multi-trajectory finite differences and reweighted finite differences, are either too computationally demanding to calculate within acceptable noise tolerances or are too biased for practical accuracy. This work presents a new reweighting-free, single-simulation formula that allows for practical, high signal-to-noise calculations of CG model sensitivity with respect to FG model interaction parameters and thermodynamic state points. This formula, the self-consistent basis (SCB) single point formula, determines the many-body sensitivity in a single step by approximating the derivative of the many-body potential projected onto the same set of trial functions as the sensitivity. A related diagnostic formula also derived in this paper is the self-consistent iterative (SCI) single point formula, which is useful for identifying the importance of many-body sources of error and verifying CG representability of observables. The SCI formula determines the many-body sensitivity iteratively via a series of partially self-consistent, variational approximations to the complete many-body sensitivity. The new, computationally efficient SCB formula shows substantially less noise than previous methods when applied to single site methanol and solvent-free sodium chloride CG models, though bias can remain a problem. It represents a novel method for calculating alchemical transferability across interaction parameters at low computational cost and with high fidelity, and the results point to new understanding of the current limits of CG model transferability.

Synthesis and characterization of an infinite sheet of metal–alkyl bonds: unfolding the elusive structure of an unsolvated alkali-metal trisalkylmagnesiate

The study of co-complexation reactions between NaCH(2)SiMe(3) and Mg(CH(2)SiMe(3))(2) has allowed the isolation and structural elucidation of the first solvent-free alkali-metal alkylmagnesiate [{NaMg(CH(2)SiMe(3))(3)}(∞)] (1) as well as the related solvent-free sodium alkyl [{(NaCH(2)SiMe(3))(4)}(∞)] (3).

Synthesis and Solid State Structures of Sterically Congested Sodium and Cesium Silyl(fluorosilyl)phosphanide Aggregates and Structural Characterization of the Trimeric Sodium Bis(trimethylsilyl)amide

Metalation of the silyl(fluorosilyl)phosphane Is2(F)Si−PH(SiR3) (3a; Is = 2,4,6-triisopropylphenyl, R3Si = Me2(PriMe2C)Si) at phosphorus with NaN(SiMe3)2 (4) in the molar ratio of 1:1 in toluene leads to the solvent-free sodium derivative 1a which forms a Na2P2-dimer in solution and in the solid state. The coordinatively unsaturated Na centers are each additionally bonded to a fluorine atom, so that a ladder-like, puckered tricyclic F2Na2P2Si2 skeleton results as the central structural motif. The same conversion of 3a into 1a under less polar reaction conditions (hexane) and the complete conversion of the silyl(fluorosilyl)phosphane Is2(F)Si−PH(SiPri3) (3b) into its Na derivative 1b is kinetically hampered and can only be achieved if 2 equiv of sodium amide 4 are employed. Excess 4 may be recovered by fractional crystallization, from which its molecular Na3N3-trimer was isolated and structurally characterized for the first time. The unusual molecular polymeric cesium phosphanide [Is2(F)Si−PCs(SiPri3)·0.5THF] (2) was prepared by the metalation of 3a with elemental cesium in toluene in the presence of little THF. The structure of 2 was determined by X-ray diffraction.

Synthesis and Structure of the Solvent-Free Sodium Aryl (NaC6H3-2,6-Mes2)2

The synthesis and first structural characterization of a solvent-free sodium aryl derivative, (NaC6H3-2,6-Mes2)2, are described. Molecules of (NaC6H3-2,6-Mes2)2 are metal-bridged dimers in which the Na+ cations are primarily coordinated to ipso phenyl and ipso mesityl carbons.