Access to Sulfur-Containing Bisheterocycles through Base-Promoted Consecutive Tandem Cyclization/Sulfenylation with...

Area of Science:

• Organic Chemistry
• Green Chemistry
• Heterocyclic Chemistry

Background:

• Synthesis of sulfur-containing heterocycles is crucial for pharmaceuticals and materials.
• Existing methods often require harsh conditions, metal catalysts, or toxic reagents.
• Development of efficient and environmentally benign synthetic routes is highly desirable.

Purpose of the Study:

• To develop a convenient and efficient tandem cyclization/sulfenylation method.
• To synthesize diverse sulfur-containing bisheterocycles.
• To utilize elemental sulfur (S8) as a sustainable building block under green chemistry conditions.

Main Methods:

• A one-step, base-mediated organic transformation.
• Reaction of o-alkynyl-phenols, -anilines, or -enaminones with elemental sulfur (S8).
• Focus on mild reaction conditions and absence of metal catalysts.

Main Results:

• Successful synthesis of diverse sulfur-containing bisheterocycles, including benzofurans, indoles, and chromones.
• Formation of two carbon-sulfur (C-S) bonds in a single step.
• Demonstrated good functional group tolerance and valuable product structures.

Conclusions:

• The developed methodology provides a facile and efficient route to sulfur-containing bisheterocycles.
• The use of elemental sulfur (S8) under green chemistry conditions offers a sustainable and practical approach.
• This method eliminates the need for metal catalysts, making it an attractive alternative for organic synthesis.