Organic Reactions in Ionic Liquids: Ionic Liquid Ethylammonium Nitrate–Promoted Knoevenagel Condensation of Meldrum's Acid With Aromatic Aldehydes

The Knoevenagel condensation of Meldrum's acid with aromatic aldehydes proceeded efficiently in a reusable ionic liquid, ethylammonium nitrate, at room temperature in the absence of any catalyst with high yields.     

RuCl3 · xH2O: A New Efficient Catalyst for Facile Preparation of 1,1‐Diacetates from Aldehydes

An efficient, facile preparation of aldehyde 1,1‐diacetates (acylals) in excellent yields catalyzed by RuCl₃ · xH₂O is described. Ketones do not react under these conditions.     

Synthesis of Aromatic Aldehydes by a Fast Method Involving Kornblum's Reaction

Aromatic aldehydes were synthesized by oxidation of corresponding halides with dimethyl sulfoxide on potassium bicarbonate by microwave irradiation. Short reaction time and high yields were obtained.     

[emim]BF4‐Promoted Chloromethylation of Aromatic Hydrocarbons

The chloromethylation of aromatic hydrocarbons proceeded efficiently using the reusable ionic liquid [emim]BF₄ as promoter. The reactions were completed in 5 h at 70°C with good yields and easy workup.     

Intramolecular Ketone-Olefin Radical Cyclization with Low-Valent Titanium Reagent: Synthesis of Benzopyrans

A novel protocol for intramolecular ketyl-olefin radical cyclization with low-valent titanium reagent is outlined. It allows the formation of the benzopyran nucleus from ortho-allyloxy propiophenones as the sole product in moderate yields via intramolecular radical cyclization.     

Stereocontrolled Transformations of trans α,β‐Aziridine Aldehydes toward Different Amino Hydroxylated Structures

The stereocontrolled condensation of methyl ketones to trans α,β‐aziridine aldehydes creates functionalized aldols, valuable precursors for different amino hydroxylated structures, such as amino alcohols, amino diols, α‐tetrahydrofuryl amides, and α‐furyl amides.     

Facile Method for One-Step Synthesis of 2,4,5-Triarylimidazoles Under Catalyst-Free,Solvent-Free,and Microwave-Irradiation Conditions

A green and efficient method for the synthesis of 2,4,5-triarylimidazoles by one-step condensation reaction of benzil, aromatic aldehyde, and ammonium acetate under catalyst-free, solvent-free, and microwave-irradiation conditions is reported. This method had many dramatic advantages, such as the short reaction time (3–5 min), good yields (80–99%), environmental friendliness, and convenient operation.     

Solvent‐Free Chemoselective Synthesis of 1,1‐Diacetates Catalyzed by Cu(NO3)2 · 3H2O

1,1‐Diacetates have been synthesized by the reaction of a variety of aldehydes with acetic anhydride in the presence of cupric nitrate as catalyst under solvent‐free conditions. Ketones were not converted to the corresponding diacetates under these conditions.     

Chemoselective and Solvent‐Free Thioacetalization of Aldehydes by a Catalytic Amount of NBS

A chemoselective, straightforward, and rapid method for thioacetalization of aldehydes by use of 1,2‐ethandithiol and a catalytic amount of N‐bromosuccinimide under solvent‐free conditions is reported. The reaction takes place in excellent yields and short reaction times.