Heterobimetallic Zinc/Strontium Catalysis: /-Selective Asymmetric Conjugate Addition of 3-Acetoxy-2-oxindoles to Alkynones.

A chiral Zn-Sr heterobimetallic catalyst system generated in situ has been developed for the first highly /-selective asymmetric conjugate addition of 3-acetoxy-2-oxindoles to alkynones. Both terminal alkynones and nonterminal alkynones could be applied to the heterobimetallic catalytic system. The corresponding 3-alkenyl-3-acyloxy-2-oxindoles were obtained in moderate to excellent yields (55-99%) with high : ratios (8:1-30:1) and high enantioselectivities (86-99% ee).

High diastereo- and enantioselective Michael addition of 3-acetoxy-2-oxindoles with nitroalkenes catalyzed by nickel/PyBisulidine.

A Ni/PyBisulidine catalyzed asymmetric Michael addition of 3-acyloxy-2-oxindoles to nitroalkenes has been developed. Various quaternary substituted 3-acyloxy-2-oxindoles were obtained with excellent yields and diastereo- and enantioselectivities in a low-toxic green solvent, ethyl acetate, with a low catalyst loading (1 mol%). The reaction process is air and moisture tolerant.

Facile construction of dibenzodioxo[3.3.1]nonanes bearing spirocyclohexadienones domino [4 + 2] cycloaddition/C(sp)-H oxidative dehydrogenation coupling reactions.

A novel palladium catalyzed homodimerization of -hydroxyphenyl substituted -QMs has been developed [4 + 2] cycloaddition/oxidative dehydrogenation coupling domino reactions. An interesting palladium catalyzed intramolecular benzyl C-H oxidation dehydrogenation to form a transannular C(sp)-O bond was found. This protocol provided an efficient method to construct various dibenzodioxo[3.

Divergent oxidative dearomatization coupling reactions to construct polycyclic cyclohexadienones.

Highly selective divergent oxidative dearomatization coupling reactions, in which the chemoselectivity is controlled by catalysts and bases, are reported herein. Three different kinds of polycyclic cyclohexadienones are produced from the same reactants (41 examples, 85-99% yield). Our method marks a novel copper- and palladium-catalyzed C-H oxidative dearomatization of phenolic derivatives.

Cooperative Heterobimetallic Zinc/Alkaline Earth Metal Catalysis: A Zn/Sr Aminophenol Sulfonamide Complex for Catalytic Asymmetric Michael Addition of 3-Acetoxy-2-oxindoles to β-Ester Enones.

A heterobimetallic zinc/strontium catalyst has been developed for the asymmetric Michael addition of 3-acetoxy-2-oxindoles to β-ester enones in high yields with excellent enantioselectivities and high diastereoselectivities. This process represents that 3-acetoxy-2-oxindoles can be used as a stable air- and base-tolerant precursor for chiral 3-substituted 3-hydroxy-2-oxindoles.

Organocatalytic asymmetric cascade 1,6-addition/hemiketalization/retro-Henry reaction of ortho-hydroxyphenyl-substituted p-QMs with α-nitroketones.

A novel organocatalytic asymmetric cascade 1,6-addition/hemiketalization/retro-Henry reaction of ortho-hydroxyphenyl-substituted p-QMs with α-nitroketones is described. A variety of novel chiral 2-(1-(4-hydroxyphenyl)ethyl)phenols are constructed for the first time with high yields (up to 92%) and excellent enantioselectivities (up to >99% ee) under mild reaction conditions. A gram-scale experiment of this process is also presented.

A homodinuclear cobalt complex for the catalytic asymmetric Michael reaction of β-ketoesters to nitroolefins.

A homodinuclear Co2/aminophenol sulfonamide complex has been developed for the asymmetric Michael reaction of β-ketoesters with nitroolefins. This procedure is capable of tolerating a wide range of substrates and excellent results (up to 99% yield, >99 : 1 dr and 98% ee) can also be obtained. Moreover, the reaction could be carried out on a 50 mmol scale without any decrease in the enantioselectivity and reactivity.

Catalytic enantioselective Henry reaction of α-keto esters, 2-acylpyridines and 2-acylpyridine -oxides.

A pre-prepared Ni-PyBisulidine complex has been developed for the catalytic asymmetric Henry reaction of α-keto esters, 2-acylpyridines and 2-acylpyridine -oxides. The corresponding β-nitro-α-hydroxy esters were obtained in good to excellent yields (up to 99%) with a high enantiomeric excess (ee) (up to 94%) with a catalyst loading of 1-2 mol%. The desired products of 2-acylpyridines and 2-acylpyridine -oxides, which were simple methyl ketones, were obtained in medium to excellent yields (up to 94%) with medium to good ee (up to 86%) by using 2 mol% of catalyst.

A novel homobimetallic nickel complex for the asymmetric direct Mannich reaction of imines: a practical method on a multi-gram scale.

A novel dinuclear Ni complex has been developed for the direct Mannich reaction of malonates with N-tosyl aryl imines with a low catalyst loading (0.1-0.05 mol%) on a preparative scale (5-50 mmol).

Re-evaluation of the interrelationships among the behavioral tests in rats exposed to chronic unpredictable mild stress.

The chronic unpredictable mild stress model of depression has been widely used as an experimental tool to investigate human psychopathology. Our objective was to provide an update on the validity and reliability of the chronic unpredictable mild stress model, by analyzing the interrelationships among the indexes using stepwise discriminant analysis and Pearson correlation coefficient to examine the possible combinations. We evaluated the depressive rats in both the presence and the absence of chronic unpredictable mild stress, using weight change, percentage of sucrose preference, coat state, splash test, open-field test, elevated plus-maze test, forced swimming test, and Morris water maze test.

The protection of meloxicam against chronic aluminium overload-induced liver injury in rats.

The present study was designed to observe the protective effect and mechanisms of meloxicam on liver injury caused by chronic aluminium exposure in rats. The histopathology was detected by hematoxylin-eosin staining. The levels of prostaglandin E2, cyclic adenosine monophosphate and inflammatory cytokines were detected by enzyme linked immunosorbent assay.

An Ni-PyBisulidine complex for the asymmetric hydrophosphonylation of aldehydes.

A novel Ni-PyBisulidine complex has been developed for the asymmetric hydrophosphonylation of aldehydes. A variety of aromatic, heteroaromatic, condensed-ring, α,β-unsaturated, and aliphatic aldehydes are found to be suitable substrates for the reaction, and the desired α-hydroxy phosphonates are obtained in up to 99% yield and 97% ee.

Effect of the PGD2-DP signaling pathway on primary cultured rat hippocampal neuron injury caused by aluminum overload.

In the present study, the agonists and antagonists of DP receptor were used to examine whether the PGD2-DP signaling pathway affects neuronal function. Primary cultured hippocampal neuron was prepared and treated with aluminum maltolate (100 μM) to establish the neuronal damage model. PGD2 and cAMP content was detected by ELISA.

The protective effect of caffeic acid on global cerebral ischemia-reperfusion injury in rats.

Ischemic stroke is a major cause of death and disability all over the world. Ischemic stroke results from a temporary or permanent reduction of cerebral blood flow that leads to functional and structural damage in different brain regions. Despite decades of intense research, the beneficial treatment of stroke remains limited.

rac-tert-Butyl 2-{5-[(4-{2-[methyl(pyri-din-2-yl)amino]ethoxy}phenyl)methyl]-2,4-dioxo-1,3-thiazolidin-3-yl}acetate.

The title compound, C(24)H(29)N(3)O(5)S, is a chiral mol-ecule which crystallizes in a centrosymmetric space group as a racemate. The thia-zolidine ring forms the dihedral angles of 29.22 (12) and 67.