Thioacetalation and Multi-Component Thiomethylative Friedel-Crafts Arylation Using BF₃SMe₂

Abstract

Herein, a method for thioacetalation using BF3SMe2 is presented. The method allows for convenient and odor-free transformation of aldehydes to methyl-dithioacetals, a simple but sparsely reported structural moiety, in good yields with a diverse set of aromatic aldehydes. In addition, a thiomethylative Friedel-Crafts reaction was discovered, affording thiomethylated diarylmethanes in good to excellent yields. The resulting diarylmethane core is of interest as it is found in many biologically active compounds, and its utility is further demonstrated as a novel precursor to unsymmetrical triarylmethanes. This work also highlights the usefulness and the synthetic capabilities of the readily available reagent BF3SMe2 beyond its reactivity profile as a dealkylation reagent.

Synthesis of a novel twisted π-conjugated macrocycle via double Friedel–Crafts reaction and its physical properties

“…S14, ESI†) compared to that of 4,4′-(phenylmethylene)bis( N , N -dimethylaniline) (Leuco Malachite Green, 5.39 ppm). 19 This result is probably attributed to the deshielding effect of the alkyne moieties.…”