Digoxin did not reduce overall mortality, but it reduced the rate of hospitalization both overall and for worsening heart failure. These findings define more precisely the role of digoxin in the management of chronic heart failure.

The scope and limitations of the ruthenium-catalyzed propargylic substitution reaction of propargylic alcohols with heteroatom-centered nucleophiles are presented. Oxygen-, nitrogen-, and phosphorus-centered nucleophiles such as alcohols, amines, amides, and phosphine oxide are available for this catalytic reaction. Only the thiolate-bridged diruthenium complexes can work as catalysts for this reaction. Results of some stoichiometric and catalytic reactions indicate that the catalytic propargylic substitution reaction proceeds via an allenylidene complex formed in situ, whereby the attack of nucleophiles to the allenylidene C(gamma) atom is a key step. Investigation of the relative rate constants for the reaction of propargylic alcohols with several para-substituted anilines reveals that the attack of anilines on the allenylidene C(gamma) atom is not involved in the rate-determining step and rather the acidity of conjugated anilines of an alkynyl complex, which is formed after the attack of aniline on the C(gamma) atom, is considered to be the most important factor to determine the rate of this catalytic reaction. The key point to promote this catalytic reaction by using the thiolate-bridged diruthenium complexes is considered to be the ease of the ligand exchange step between a vinylidene ligand on the diruthenium complexes and another propargylic alcohol in the catalytic cycle. The reason why only the thiolate-bridged diruthenium complexes promote the ligand exchange step more easily with respect to other monoruthenium complexes in this catalytic reaction should be that one Ru moiety, which is not involved in the allenylidene formation, works as an electron pool or a mobile ligand to another Ru site. The catalytic procedure presented here provides a versatile, direct, and one-step method for propargylic substitution of propargylic alcohols in contrast to the so far well-known stoichiometric and stepwise Nicholas reaction.

A convenient and straightforward one-pot reaction of propargylic alcohols bearing a terminal alkyne moiety with amides by the sequential action of ruthenium and gold catalysts gives the corresponding substituted oxazoles in good yields with a complete regioselectivity.

The time-delayed feedback control mechanisms of the nervous system are continuously subjected to the effects of uncontrolled random perturbations (herein referred to as noise). In this setting the statistical properties of the fluctuations in the controlled variable(s) can provide non-invasive insights into the nature of the underlying control mechanisms. We illustrate this concept through a study of stick balancing at the fingertip using high speed motion capture techniques. Experimental observations together with numerical studies of a stochastic delay differential equation demonstrate that on time scales short compared to the neural time delay ("fast control"), parametric noise provides a non-predictive mechanism that transiently stabilizes the upright position of the balanced stick. Moreover, numerical simulations of a delayed random walker with a repulsive origin indicate that even an unstable fixed point can be transiently stabilized by the interplay between noise and time delay. In contrast, on time scales comparable to the neural time delay ("slow control"), feedback and feedforward control mechanisms become more important. The relative contribution of the fast and slow control mechanisms to stick balancing is dynamic and, for example, depends on the context in which stick balancing is performed and the expertise of the balancer.

Reactions of propargylic alcohols bearing a terminal alkyne moiety with aromatic compounds in the presence of a catalytic amount of thiolate‐bridged diruthenium complexes give the corresponding propargylated aromatic compounds in high yields with complete selectivity. Intramolecular reactions of propargylic alcohols bearing an aromatic moiety proceed smoothly to afford the cyclized products in high yields with complete selectivity. The stoichiometric reaction of the ruthenium–allenylidene complex [Cp*RuCl(μ2‐SMe)2RuCp*(=C=C=CHPh)]BF4 (Cp* = η5‐C5Me5) with 10 equiv. 2‐methylfuran results in the formation of 2‐methyl‐5‐(1‐phenyl‐2‐propynyl)furan in 34 % yield, indicating that these catalytic reactions proceed via ruthenium–allenylidene intermediates. The reaction is considered to be an electrophilic substitution of aromatic compounds by the ruthenium‐stabilized propargyl cation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The synthesis of structurally diverse 2-aryl/heteroaryloxazolines from nitriles and aminoalcohols has been achieved under metal- and catalyst-free conditions in good to excellent yields. An array of functional groups are well-tolerated, thus, allowing the introduction of many important biologically active motifs such as azoles, ring-fused azoles, saturated heterocyclics, and amines in 2-aryloxazoline scaffolds. An evaluation of the antioxidant properties using the DPPH (diphenyl picryl hydrazyl) assay method shows the pyrrole-functionalized 2-aryloxazoline to be the best antioxidant among all the synthesized 2-aryl/heteroaryloxazolines.

1,1-Diaryl-1-penten-4-yn-3-ols react with diphenylphosphine oxide in the presence of a thiolate-bridged diruthenium complex as a catalyst and give high yields of aryl(diphenyl)phosphine oxide products via an initial substitution followed by a cyclization at the produced allene intermediate. [reaction: see text]

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