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

Area of Science:

• Organic Chemistry
• Synthetic Methodology

Background:

• Thioacetals are important structural motifs, though their synthesis can be challenging.
• Diarylmethanes are prevalent in biologically active molecules.
• Boron trifluoride-dimethyl sulfide (BF₃SMe₂) is a known reagent with potential for broader synthetic applications.

Purpose of the Study:

• To develop a convenient and odor-free method for thioacetalation of aldehydes.
• To explore new synthetic transformations using BF₃SMe₂.
• To demonstrate the utility of BF₃SMe₂ in synthesizing diarylmethanes and their derivatives.

Main Methods:

• Thioacetalation of various aromatic aldehydes using BF₃SMe₂.
• Development of a thiomethylative Friedel-Crafts reaction catalyzed by BF₃SMe₂.
• Synthesis of unsymmetrical triarylmethanes from the diarylmethane products.

Main Results:

• Successful thioacetalation of aromatic aldehydes to methyl-dithioacetals in good yields.
• Discovery of a thiomethylative Friedel-Crafts reaction yielding thiomethylated diarylmethanes in good to excellent yields.
• Demonstration of diarylmethanes as precursors to unsymmetrical triarylmethanes.

Conclusions:

• BF₃SMe₂ is a versatile reagent for efficient and odor-free thioacetalation.
• A novel thiomethylative Friedel-Crafts reaction expands synthetic routes to diarylmethanes.
• This work showcases the synthetic utility of BF₃SMe₂ beyond its known applications.