Synthesis and Spectroscopic Studies of New Substituted Dinuclear η5-4,5,6,7-Tetrahydroindenyl Ruthenium Complexes

New complexes of bis(1,3-dimethyl-4,5,6,7-tetrahydroindenyl)diruthenium tetracarbonyl and bis(3-methyl-1-phenyl-4,5,6,7-tetrahydroindenyl)diruthenium tetracarbonyl were prepared from the corresponding substituted tetrahydroindene and ruthenium carbonyl. The ligand systems were obtained by the reactions of methyl magnesium iodide and phenyl magnesium bromide with 3-methyl-2,3,4,5,6,7-hexahydroind-8(9)en-1-one.     

A convenient ultrasound-promoted regioselective synthesis of fused polycyclic 4-aryl-3-methyl-4,7-dihydro-1H-pyrazolo[3,4-b]pyridines

Fused polycyclic 4-aryl-3-methyl-4,7-dihydro-1H-pyrazolo[3,4-b]pyridines were obtained in a three-component regioselective reaction of 5-amino-3-methyl-1H-pyrazole, 2H-indene-1,3-dione and arylaldehydes in ethanol under ultrasound irradiation. This rapid method produced the products in short reaction times (4–5 min) and excellent yields (88–97%).     

Convenient Ultrasound-Promoted Regioselective Synthesis of Fused 6-Amino-3-methyl-4-aryl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile

A multicomponent, catalyst-free reaction for the synthesis of fused 6-amino-3-methyl-4-aryl-1H-pyrazolo [3,4-b] pyridine-5-carbonitrile from 3-amino-5-methylpyrazole, malononitrile, and substituted aldehydes under ultrasound irradiation in short reaction times (8–10 min) with good yields (85–98%) is reported.

One-pot facile conversion of Baylis-Hillman adducts into 1,5-diarylpyrazoles using microwave irradiation

Several Baylis-Hillman adducts were prepared by the reaction of appropriate arylaldehydes with methyl vinyl ketone in the presence of imidazole and a catalytic amount of L-proline, in 55–90% yields. An easy transformation of these adducts into 1,5-diarylpyrazoles was achieved using microwave irradiation (400 W) with short reaction times (1–3 min) and high yields (80–91%).     

Asymmetric Michael Addition Catalyzed by Aluminum Lithium Bis-(R)-binaphthoxide

Enantiomerically pure aluminum lithium bis-(R)-binaphthoxide [(R)-ALB] was synthesized and used to catalyze asymmetric Michael addition of diethyl malonate to ethyl crotonate.     

An Efficient Method for the Synthesis of 5-Arylisoxazoles from Benzyl Cobaloximes Using Microwave Irradiation

A new and rapid method is described for the synthesis of 5-arylisoxazoles from benzyl cobaloximes using microwave irradiation.     

Solvent-free, ruthenium-catalyzed, regioselective ring-opening of epoxides, an efficient route to various 3-alkylated indoles

Ruthenium-catalyzed regioselective ring-opening of aliphatic and aryl epoxides under solvent-free conditions is reported. It was found that RuCl₃·nH₂O catalyzes the Friedel-Crafts alkylation of indoles, providing 3-alkylated derivatives in good yields under mild reaction conditions.     

Evaluating the Synthesis of Bis‐pyrazolines

The bis‐cyclization of chalcone with thiosemicarbazide under basic condition led to the formation of new compounds, thiocarbamoyl bis‐pyrazoline derivatives. Bis‐chalcones were prepared by a Claisen–Schmidt condensation between 1 mol bis‐aldehyde and 2 mol acetophenone derivatives in the presence of sodium hydroxide as a catalyst. The structures of all compounds were elucidated by IR, ¹H NMR, and ¹³C NMR spectral data and by elemental analyses.     

Synthesis of Methyl 3,6-Dioxo-endo-tricyclo[6.2.1.02,7]undeca- 4,9-diene-2-carboxylate as Synthetic Intermediate for Conduritol Derivatives

Gentisic acid reacted with methyl iodide in HMPA to give 94% of the corresponding methyl ester. Its oxidation with Ag₂O in toluene afforded 57% of methoxycarbonylbenzoquinone as yellow crystals. Reaction of the latter with cyclopentadiene resulted in formation of methyl 3,6-dioxotricyclo[6.2.1.02,7]undeca-4,9-diene-2-carboxylate (21%).     

Introduction of Ag/CuO/MCM‐48 as an efficient catalyst for the one‐pot synthesis of novel pyran‐pyrrole hybrids

Bimetallic silver and copper incorporated mesoporous MCM‐48 (Ag/CuO/MCM‐48) was synthesized by simple wet‐impregnation method. The knowledge about its structural properties was gathered by means of Fourier transform‐infrared, energy‐dispersive X‐ray, X‐ray diffraction, field emission‐scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller analyses. The catalytic activity of Ag/CuO/MCM‐48 was examined in the one‐pot three‐component reaction of 3‐(1‐methyl‐1H‐pyrrol‐2‐yl)‐3‐oxopropanenitrile, malononitrile and various aromatic aldehydes leading to novel pyran‐pyrrole hybrid derivatives in reduced reaction times (5–10 min) and excellent yields (88–97%). Application of Ag/CuO/MCM‐48 as a potent heterogeneous catalyst with good reusability up to five times, use of ethanol as an eco‐compatible medium and chromatography‐free work‐up are some crucial green aspects of this procedure.