Synthesis of Densely Substituted 1,3-Butadienes through Acid-Catalyzed Alkenylations of α‑Oxoketene Dithioacetals with Aldehydes

Aldehydes were proved to be viable reagents for implementing alkenylation of α-oxoketene dithioacetals. AlCl₃ was found to be the best catalyst. The established reaction opened an avenue to access densely substituted 1,3-butadiene derivatives. The obtained product bears multiple reactive sites that can be converted into various valuable molecules

Synthesis of Densely Substituted 1,3-Butadienes through Acid-Catalyzed Alkenylations of α‑Oxoketene Dithioacetals with Aldehydes

Aldehydes were proved to be viable reagents for implementing alkenylation of α-oxoketene dithioacetals. AlCl₃ was found to be the best catalyst. The established reaction opened an avenue to access densely substituted 1,3-butadiene derivatives. The obtained product bears multiple reactive sites that can be converted into various valuable molecules

Ionic Liquid as an Efficient Promoting Medium for Fixation of CO₂: Clean Synthesis of α-Methylene Cyclic Carbonates from CO₂ and Propargyl Alcohols Catalyzed by Metal Salts under Mild Conditions

Reactions of propargylic alcohols with CO2 in a [BMIm][PhSO3]/CuCl catalytic system to produce the corresponding α-methylene cyclic carbonates were conducted with high yields. Mild reaction conditions, enhanced rates, improved yields, and recyclable ionic liquid catalyst systems are the remarkable features exhibited in this process. Furthermore, the use of large amounts of tertiary amines as well as nitrogen-containing organic solvent as employed in previously studies was avoided

Synthesis of Quinoline-Fused 1‑Benzazepines through a Mannich-Type Reaction of a C,N-Bisnucleophile Generated from 2‑Aminobenzaldehyde and 2‑Methylindole

Various quinoline-fused 1-benzazepine derivatives were synthesized using the C,N-1,6-bisnucleophile generated in situ from <i>o</i>-aminobenzaldehyde and 2-methylindole through a Mannich-type reaction

Silica-Supported Sodium Sulfonate with Ionic Liquid: A Neutral Catalyst System for Michael Reactions of Indoles in Water

A neutral catalytic system for Michael reactions of indoles has been developed by combining silica-supported benzenesulfonic acid sodium salt with hydrophobic ionic liquid in water. An efficient hydrophobic environment could be created on the surface of the silica−sodium material under the conditions. Various indole derivatives and α,β-unsaturated carbonyl compounds including some acid-labile substrates were successfully applied to this system with water as the sole solvent to afford the desired Michael adducts in high yields

Synthesis of Quinoline-Fused 1‑Benzazepines through a Mannich-Type Reaction of a C,N-Bisnucleophile Generated from 2‑Aminobenzaldehyde and 2‑Methylindole

Various quinoline-fused 1-benzazepine derivatives were synthesized using the C,N-1,6-bisnucleophile generated in situ from <i>o</i>-aminobenzaldehyde and 2-methylindole through a Mannich-type reaction

2‑Methylindole as an Indicative Nucleophile for Developing a Three-Component Reaction of Aldehyde with Two Different Nucleophiles

2-Methylindole was used as an indicative nucleophile for rapid screening of MCRs of aldehydes with two different nucleophiles. By removal of some samples that have characteristic color associated with the generation of di­(indolyl)­methane derivatives the difficulties encountered in the product analysis were alleviated significantly

Ring-Opening Reactions of 2-Alkoxy-3,4-dihydropyrans with Thiols or Thiophenols

An electrophilic ring-opening reaction of 2-alkoxy-3,4-dihydropyran with a thiophenol or thiol is developed for the first time. The generated product contains not only a 1,3-dicarbonyl moiety but also a fragment of bis(alkylthio)methane. A possible mechanism is also proposed on the basis of postulating a ring-opening monotransthioacetalization product, which was prepared by using LiBr as catalyst as an intermediate

Selectivity Enhancement of Silica-Supported Sulfonic Acid Catalysts in Water by Coating of Ionic Liquid

Coating of silica-supported sulfonic acid catalysts with hydrophobic ionic liquid leads to a significant improvement of catalyst selectivity. Many organic reactions, including Prins cyclization, cycloaddition of epoxide to aldehyde, and dehydrative etherification of secondary benzyl alcohols, proceed well in formalin or pure water. In particular, tandem dehydration/Prins cyclization reactions of tertiary and secondary alcohols with formaldehyde were developed for the first time

Bismuth(III) Triflate Catalyzed Three-Component Reactions of Indoles, Ketones, and α‑Bromoacetaldehyde Acetals Enable Indole-to-Carbazole Transformation

A three-component reaction of indoles, α-bromoacetaldehyde acetals, and ketones was developed by using bismuth­(III) triflate as the catalyst to realize a straightforward approach for synthesizing carbazole derivatives. The reaction was established mechanistically through the autotandem catalysis of Bi­(OTf)₃ in the following two steps: (i) Friedel–Crafts-type alkylation of indole with α-bromoacetaldehyde acetal, which produced a tryptaldehyde-type intermediate and (ii) [4 + 2] annulation of this intermediate with the ketone component