Non-Metal Lewis Acid-Catalyzed Cross-Claisen Condensation for β-Keto Esters

In this work, we disclose a new catalytic and high chemoselective cross-Claisen condensation of esters. In the presence of TBSNTf2 as non-metal Lewis acid, various esters can undergo cross-Claisen condensation to form β-keto esters which are important building blocks. Compared with traditional Claisen condensation, this process, employing silyl ketene acetals (SKAs) as carbonic nucleophile to achieve cross-Claisen condensation, has mild conditions and good tolerance of functional groups.