Photoinduced, Palladium-Catalyzed Enantioselective 1,2-Alkylsulfonylation of 1,3-Dienes

Abstract

The chiral allylic sulfonylated group is a unique structural motif embedded in a range of natural products and pharmaceuticals. Notably, the synthesis of structurally diverse chiral allylic sulfonylated derivatives via alkylsulfonylation of 1,3-dienes remains underexplored because of its inherent challenges in stereocontrol and regioselectivity. Herein, photoinduced, palladiumcatalyzed enantioselective 1,2-alkylsulfonylation of conjugated 1,3-dienes is described. A wide variety of alkyl bromides, 1,3-dienes, and sodium sulfinates could be facilely coupled to generate value-added chiral allylic sulfonylated derivatives with high enantioselectivity. Finally, the utility of this enantioselective difunctionalization protocol was demonstrated in pharmaceutical analogue synthesis.

Enantioselective Synthesis of Allylic Sulfones via Rhodium-Catalyzed Direct Hydrosulfonylation of Allenes and Alkynes

“…For these reasons, the development of efficient methods for the preparation of sulfone-containing compounds continues to be an active research area of great interest, especially α-chiral sulfones . Although methods for the preparation of α-chiral sulfones have increasingly gained attention, methods to prepare these important moieties with high enantiocontrol remain a formidable challenge, and the current methods − are not without their drawbacks.…”

“…In conclusion, we have developed the first direct rhodium-catalyzed enantioselective hydrosulfonylation of allenes and alkynes. Although methods to prepare chiral sulfones have been successful, the known methods − are typically not as direct and can be narrow in scope. The current protocol is atom-economical and operationally simple, and the reaction is high-yielding and highly regio- and enantioselective over a broad scope of substrates to provide the products in a single step.…”