The treatment of β,γ-unsaturated α-ketoesters with phenols in the presence of trityl chloride and 4 Å molecular sieves in refluxing trifluoroacetic acid afforded 4-aryl-2H-chromenes in high yields, in which a reverse of the regiochemistry of Jørgensen-Rutjes chromane synthesis was observed. The isolation of 4H-chromene intermediates, confirmed by single-crystal X-ray analysis, indicates that th...

The Friedel-Crafts alkylation constitutes one of the most important reactions for formation carbon-carbon bonds. Here, we report using squalene-hopene cyclases, which provides a biological alternative to traditional strategy. cyclase from Alicyclobacillus acidocaldarius (AacSHC) and variants have been demonstrated broad substrate reaction scope, making them valuable potential applications in bi...

The Friedel–Crafts acylation of 2-methoxynaphthalene was carried out in the liquid-phase batch conditions using Hmordenite, H-beta and H-Y zeolite as catalysts. All the catalysts showed 35–40% conversion in the temperature range of 100–150◦C. 1-Acyl-2-methoxynaphthalene was formed as the primary product. When acetyl chloride was used as the acylating agent, a higher yield of 6-acyl-2-methoxynap...

The formation of C C bonds is a central aspect of synthetic organic chemistry. However, in biocatalysis only few enzymes capable to perform this reaction are known, among which aldolases, transketolases, and hydroxynitril lyases have been investigated thoroughly. Some have even found their way into industrial applications. Friedel–Crafts alkylation is a classic organic reaction of great importa...