Facile synthesis of 1-naphthols through a copper-catalyzed arylation of methyl ketones with o-bromoacetophenones

The coupling reactions of simple methyl ketones with o-bromoacetophenones and subsquential cyclization reactions were realized to produce a range of 1-naphthols. These cascade reactions were initiated by a rare Cu-catalyzed arylation reaction of methyl ketones with aromatic bromides.     

Eco-friendly synthesis of 2-substituted-2,3-dihydro-4(1H)-quinazolinones in water

2-Substituted-2,3-dihydro-4(1H)-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst.This protocol has advantages of high yield,simple work-up and environmental friendly procedure.     

Characterization and chemical behavior of submonolayer coverages of titania on a Pt foil

The interaction between submonolayer titania coverages and Pt foil has been studied by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). The submonolayer titania can be fully oxidized to TiO₂ at 923 K under 10⁻⁸ Torr O₂, and partially oxidized to TiO_x at lower oxidation temperatures. The oxidized surface can be reduced by annealing to 1000 K or higher, or by heating in H₂ at 823 K, or by interacting with surface carbon formed from acetone decomposition. Under certain conditions (e.g., hydrogen reduction at 923 K), the surface titania can be fully reduced to metallic Ti which diffuses into bulk Pt readily. The reduced metallic Ti can resurface when the surface is oxidized at 923 K. Both XPS and HREELS data indicate the existence of subsurface oxygen, which plays an important role for the diffusion of Ti into and out of the Pt foil. Although no special interfacial active sites were revealed by HREELS studies of adsorbed acetone and CO, some TPD and XPS data suggest the presence of sites active for acetone decomposition.     

Iodine as a novel and efficient reagent for the synthesis of α-aminonitriles by a three-component condensation of carbonyl compounds, amines, and trimethylsilyl cyanide

A straightforward and general method has been developed for the synthesis of α-aminonitriles by simply combining aldehydes or ketones, amines, and trimethylsilyl cyanides in the presence of a catalytic amount of molecular iodine at room temperature.     

Novel three-component tandem reactions of cyclic mono ketones, isatin and sarcosine: formation of dispiropyrrolidines

One-pot, three-component tandem reactions of cyclic mono ketones, isatin and sarcosine affording dispiropyrrolidines stereoselectively are reported for the first time.     

Novel organic catalysts for the direct enantioselective α-oxidation of carbonyl compounds

The proline-derived N-sulfonylcarboxamide-catalyzed direct enantioselective α-oxidation of ketones and aldehydes with nitrosobenzene is presented. The reactions proceed smoothly furnishing the corresponding α-aminoxylated compounds in good yields with up to >99% ee. The proline-derived N-sulfonylcarboxamides were also found to be excellent catalysts for the direct enantioselective nitroso Diels-Alder-type reaction between nitrosobenzene and α,β-unsaturated cyclic ketones yielding the corresponding bicyclic Diels-Alder adduct products with up to >99% ee. The proline-derived N-sulfonylcarboxamides represent a readily available and highly modular novel type of organic catalyst.     

Facile One‐Pot Multicomponent Synthesis of β‐Acetamido Ketones with Amberlyst‐15 as Heterogeneous Catalyst

The one‐pot multicomponent coupling of an aromatic aldehyde, an enolizable ketone or keto ester, acetonitrile, and acetyl chloride at room temperature in the presence of Amberlyst‐15 as catalyst affords β‐acetamido ketones in high yields. The inexpensive catalyst works under heterogeneous conditions and can be readily reused.     

A novel carbocatalytic hydride transfer strategy for efficient reduction of structurally different aldehydes and ketones in water

Reduced graphene oxide (rGO)–NaBH₄ is reported as mild and efficient catalyst-system for chemo-/regioselective reduction of structurally different aliphatic, aromatic as well as α,β-unsaturated aldehydes and ketones in water. The rGO was prepared by reducing graphene oxide using Tulsi leaf extract as bio-reductant. Operational simplicity, ambient reaction condition, high yield of pure products (80–97%), no by-product formation, no use of column chromatography for purification are the salient features of the envisaged protocol. Furthermore, the recovered TRGO was recycled and reused for subsequent reductions up to five times without any loss in activity.     

A simple,mild, and efficient method for the preparation of α,α-dichloroketones with DCDMH catalyzed by ammonium chloride

New process that can selectively prepare α,α-dichloro ketones from various ketones with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) using ammonium chloride as a catalyst is reported. The effects of ammonium salts, solvents, DCDMH, and reaction temperature were investigated. Under the optimal condition, most of α,α-dichlorinated products were selectively obtained in 86–98% yield.     

A new type of amino amide organocatalyzed enantioselective crossed aldol reaction of ketones with aromatic aldehydes

A new type of amino amide organocatalysts was designed and synthesized from commercially available amino acids in easy steps. Their catalytic activities were examined in enantioselective crossed aldol reaction of various acyclic and cyclic ketones with aromatic aldehydes to afford the corresponding chiral anti-aldol adducts with good to excellent chemical yields, diastereoselectivities and enantioselectivities (up to 99%, up to syn:anti?=?1:99, up to 97% ee).