Ring-Opening 1,3-Sulfonylation-Fluorination of Donor-Acceptor Cyclopropanes: Three-Component Access to γ-Fluorosulfones.

A general method for 1,3-bisfunctionalization of donor-acceptor (D-A) cyclopropanes using sulfinate salts and electrophilic fluorination reagents is described. Utilizing Lewis acid catalysis, nucleophilic ring-opening by the sulfinate anion followed by trapping of electrophilic fluorine by the anionic intermediate leads to the formation of γ-fluorosulfones. To the best of our knowledge, this is the first direct one-step synthesis of sulfones fluorinated in the γ-position from a carbon backbone. A mechanistic proposal is presented based on experimental evidence.