Access to Conjugated Dienes and Cyclic Allenes via a Diazo-Dithiane Rearrangement Cascade

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Developing novel synthetic methodologies is crucial for accessing complex organic molecules.
• Transition-metal-free reactions are highly desirable for sustainability and cost-effectiveness.
• Understanding diazo compound reactivity beyond carbene pathways remains an active research area.

Purpose of the Study:

• To develop a novel, transition-metal-free cascade reaction.
• To explore the utility of anion relay chemistry (ARC) in organic synthesis.
• To access diverse sulfur-containing conjugated dienes and cyclic allenes.

Main Methods:

• A base-promoted cascade reaction between alkynyl-1,3-dithianes and α-diazodiesters.
• Utilizing anion relay chemistry (ARC) involving a 1,3-sulfur rearrangement.
• One-pot synthesis enabling divergent product formation.

Main Results:

• Successful development of a transition-metal-free cascade reaction.
• Demonstration of selective 1,3-sulfur rearrangement via ARC.
• Divergent synthesis of eight-membered sulfur-containing conjugated dienes and cyclic allenes.
• Unveiling novel reactivity of diazo compounds.

Conclusions:

• The developed method offers a powerful one-pot strategy for synthesizing complex sulfur-containing molecules.
• This work expands the scope of diazo chemistry and highlights the potential of sulfur-based anionic processes.
• The transition-metal-free nature of the reaction enhances its synthetic applicability and sustainability.