Asymmetric Auto-Tandem Palladium Catalysis for 2,4-Dienyl Carbonates: Ligand-Controlled Divergent Synthesis

Developing new asymmetric auto-tandem catalysis processes, especially in a divergent manner, is highly attractive but extremely challenging. Presented herein is a palladium-catalyzed auto-tandem reaction between 2,4-dienyl carbonates and o-TsNH arylimines or trifluoroacetophenones that proceeds through a consecutive N-allylation, vinylogous addition, pi-sigma-pi isomerization, and another N-allylation sequence. Importantly, switchable diastereodivergent synthesis could be achieved by tuning the chiral bisphosphine ligands, which led to the construction of a broad spectrum of fused tetrahydroquinoline architectures with moderate to excellent enantioselectivity. Ligand control even enabled effective access to regiodivergent azetidine or chemodivergent beta-H elimination with fair enantioselectivity, further showing the versatility of the current auto-tandem catalysis.

Automated summary

This study presents the development of a new asymmetric auto-tandem catalysis process, which allows for the synthesis of diverse compounds with excellent stereocontrol. The use of chiral ligands enables the switchable diastereodivergent synthesis, demonstrating the versatility of this auto-tandem catalysis.