Photochemical Wolff Rearrangement Initiated Generation and Subsequent ?-Chlorination of C1 Ammonium Enolates

The enantioselective synthesis of alpha-chlorinated carboxylic acid esters with er up to 99:1 and yields up to 82% was achieved via a one-pot multistep protocol starting from alpha-diazoketones. This process proceeds via a photochemical Wolff rearrangement, trapping of the generated ketene with a chiral Lewis base catalyst, subsequent enantioselective alpha-chlorination, and a final nucleophilic displacement of the bound catalyst. The obtained products were successfully utilized for stereospecific nucleophilic displacement reactions with N-and S-nucleophiles.

Automated summary

Enantioselective synthesis of alpha-chlorinated carboxylic acid esters was achieved with er up to 99:1 and yields up to 82% via a one-pot multistep protocol starting from alpha-diazoketones. This process involves a photochemical Wolff rearrangement, enantioselective alpha-chlorination using a chiral Lewis base catalyst, and a final nucleophilic displacement of the bound catalyst. The resulting products were successfully used for stereospecific nucleophilic displacement reactions with N- and S-nucleophiles.