Ring Construction by 1,1-Carboboration; Making Anthracene Derivatives from a Tetra(alkynyl)benzene

1,2,4,5-Tetrakis(trimethylsilylethynyl)benzene reacted with two molar equivalents of the boranes R−B(C₆F₅)₂ (R=C₆F₅, Me, Ph) in a series of sequential 1,1-carboboration reactions to give ca. 1 : 1 mixtures of the two-fold benzannulated products, namely the respective C_2h and C_2v symmetric tetra-silyl, bis-boryl substituted anthracenes. Their active B(C₆F₅)₂ substituents were used for consecutive Suzuki-Miyaura C−C coupling reactions to give boron-free phenyl or 2-pyridyl substituted anthracene products.     

Preface: Regression methods based on OR techniques and computational aspects in management,economics and finance

Annals of Operations Research -     

Ultrasound-assisted synthesis and anticancer evaluation of new pyrazole derivatives as cell cycle inhibitors

We designed new pyrazole derivatives as inhibitors of the cell cycle kinases and developed a simple environmentally sustainable synthesis process. We synthesized the pyrazolyl thiourea derivatives using rapid ultrasound mediated methods and confirmed their structures by NMR and IR spectra. The apoptosis and necrosis inducing effects of the new compounds were investigated. Cell cycle analysis and expression of genes involved in apoptosis, cell cycle and xenobiotic metabolism were studied. The compounds presented modest apoptotic effects in human cancer cells. The N-[[3-(4-bromophenyl)-1H-pyrazol-5-yl]carbamothioyl]-4-chloro-benzamide compound (4e) induced a significant increase of cells in G2/M phases in conjunction with an increased expression of cyclin A and cyclin B, emerging as a promising anticancer drug, to be further developed in animal models of cancer.     

Behavior of the Hermite sheet with respect to theHurst index

We consider a $d$-parameter Hermite process with Hurst index $\mathbf{H}=(H_1,..,H_d)\in {\left(\frac{1}{2},1\right)}^d$ and we study its limit behavior in distribution when the Hurst parameters $H_i,i=1,..,d$ (or a part of them) converge to $\frac{1}{2}$ and/or 1. The limit obtained is Gaussian (when at least one parameter tends to $\frac{1}{2}$) and non-Gaussian (when at least one-parameter tends to 1 and none converges to $\frac{1}{2}$).     

Second-Order Optimality Conditions in Locally Lipschitz Inequality-Constrained Multiobjective Optimization

Journal of Optimization Theory and Applications - The main goal of this paper is to give some primal and dual Karush–Kuhn–Tucker second-order necessary conditions for the existence of a...     

Leaving us with fond memories,smiles, SMILES and,alas, tears: a tribute to David Weininger, 1952–2016

David Weininger’s career, accomplishments, genius, and friendship are warmly remembered by several of his colleagues, friends, and admirers.     

Thermooxidative stabilization of a MDI

Samples of flexible PU foam were prepared from a polyol (Elastoflex W 5516/115) and an isocyanate prepolymer (Iso 145/8), both commercial Elastogram products. For the thermooxidative stabilization, two phenolic compounds were used, separately or in mixture. These compounds were: 2,6-di-t-butyl-4-methyl-phenol (non-reactive) (AO-1), 3,5-di-t-butyl-4-hydroxy-benzyl alcohol (reactive, AO-2), used in total mass% of 0.3/1.5. The TG/DTG/DTA curves were drawn up in dynamic air, with a heating rate of 10 °C min⁻¹, until 500 °C. For the unstabilized sample a single thermodegradative TG step, with a maximum rate at 268–270 °C was observed, whereas for the stabilized samples, supplementary steps at higher temperature were observed. The changes in the TG/DTG/DTA parameters are not in a single relationship with the mass% of the stabilizator, due to the following: AO-1 is easily migrated out from PV, especially, at higher concentrations. AO-2 had positive effect at all studied concentrations. But the most remarkable effect is the synergetic effect of a 1:1 mixture of AO-1 and AO-2.     

Reaction of Moore's ketene (tert-butylcyanoketene) with 1,3-cyclopentadiene and 1,3-cyclohexadiene. Is periselectivity controlled by the dynamic of trajectories at the bifurcation point?

The cycloaddition reaction of tert-butylcyanoketene (TBCK, Moore's ketene) with 1,3-cyclopentadiene yields the [2+2] product, namely cyclobutanone 9. TBCK and 1,3-cyclohexadiene provide the cyclobutanone 10 and some of the ether 11. Both reactions yielding the cyclobutanones (9 and 10, respectively) are reversible. Cyclobutanone 10 is converted thermally and irreversibly into the bicyclic ether 11 via a [3,3] sigmatropic rearrangement (oxo-Cope). The X-ray single crystal data for the ether 11 confirms that the CN and the ether oxygen are in a trans configuration. Data provided by density functional calculations at B3LYP/6-311++G(d,p) level mirror the X-ray data.Furthermore, the relative thermodynamic stabilities (ΔG calculated at 273 °C, 1 atm) of the most relevant isomers of 10 at mPWB1K/6-31+G(d,p) level of theory is provided. Details of the transition states that: (i) leads to cyclobutanone 10 from TBCK and 1,3-cyclohexadiene, and (ii) the oxo-Cope rearrangement of cyclobutanone 10 to produce ether 11 are provided.