Synthesis, C-H bond functionalisation and cycloadditions of 6-styryl-1,2-oxathiine 2,2-dioxides

Area of Science:

• Organic Chemistry
• Heterocyclic Chemistry
• Synthetic Methodology

Background:

• 1,2-oxathiine 2,2-dioxides are versatile heterocyclic scaffolds.
• Efficient synthetic routes and functionalization strategies are crucial for exploring their chemical space.

Purpose of the Study:

• To develop a novel and efficient synthesis of 6-styryl-1,2-oxathiine 2,2-dioxides.
• To investigate the C-H functionalization and cycloaddition reactions of these oxathiine derivatives.
• To synthesize novel substituted analogues and explore their potential applications.

Main Methods:

• Two-step synthesis involving regioselective sulfene addition and Cope elimination.
• Palladium-catalyzed direct C-H bond functionalization.
• Bromination followed by Suzuki cross-coupling.
• Cycloaddition reactions with benzyne and 4-phenyl-1,2,4-triazoline-3,5-dione.

Main Results:

• Efficient synthesis of 6-styryl-1,2-oxathiine 2,2-dioxides achieved.
• Successful C-3 (hetero)arylation via direct C-H functionalization and Suzuki coupling.
• Novel fused triazolopyridazine dioxides synthesized through cycloaddition with 4-phenyl-1,2,4-triazoline-3,5-dione.
• Low yields of substituted naphthalenes obtained from benzyne cycloaddition.

Conclusions:

• The developed synthetic protocol provides access to valuable 1,2-oxathiine 2,2-dioxide derivatives.
• C-H functionalization offers an efficient route to diverse analogues.
• Cycloaddition reactions lead to novel fused heterocyclic systems with potential for further exploration.