Zinc Promoted Cross‐Electrophile Sulfonylation to Access Alkyl–Alkyl Sulfones

Abstract

Abstract The transition metal‐catalyzed multi‐component cross‐electrophile sulfonylation, which incorporates SO2 as a linker within organic frameworks, has proven to be a powerful, efficient, and cost‐effective means of synthesizing challenging alkyl–alkyl sulfones. Transition metal catalysts play a crucial role in this method by transferring electrons from reductants to electrophilic organohalides, thereby causing undesirable side reactions such as homocoupling, protodehalogenation, β‐hydride elimination, etc. It is worth noting that tertiary alkyl halides have rarely been demonstrated to be compatible with current methods owing to various undesired side reactions. In this work, a zinc‐promoted cross‐electrophile sulfonylation is developed through a radical‐polar crossover pathway. This approach enables the synthesis of various alkyl–alkyl sulfones, including 1°‐1°, 2°‐1°, 3°‐1°, 2°‐2°, and 3°‐2° types, from inexpensive and readily available alkyl halides. Various functional groups are well tolerated in the work, resulting in yields of up to 93%. Additionally, this protocol has been successfully applied to intramolecular sulfonylation and homo‐sulfonylation reactions. The insights gained from this work shall be useful for the further development of cross‐electrophile sulfonylation to access alkyl–alkyl sulfones.

Keywords

• alkyl–alkyl sulfone
• catalyst‐free
• cross‐electrophile coupling
• organic halides
• sulfonylation