TOWARDS AN ENANTIOSELECTIVE AZA-PIANCATELLI REARRANGEMENT: SYNTHESIS OF A HIGHLY SOLUBLE TRIP CATALYST
Authors:Aurora Ginzburg, Sameh Helmy
Mentor:Javier Read de Alaniz, Assistant Professor of Chemistry, UCSB
An enantioselective aza-Piancatelli rearrangement has been developed using a chiral phosphoric acid as the stereocontrolling element. The new methodology provides direct access to enantioenriched 4-aminocyclopentenones, a versatile building block for synthetic chemistry. Using commercially available phosphoric acid TRIP the products could be obtained in up to 47% ee. However, due to the poor solubility of TRIP in acetonitrile, which is required for the rearrangement, reaction times exceeded 7 days. In this work, we test if a more soluble derivative of the TRIP catalyst would help increase reaction rate and potentially the enantioselectivity. To increase solubility alkyl chains were attached to the scaffold of the TRIP catalyst. The synthesis of 6,6’-dioctyl-TRIP is described, along with the effects of the more soluble catalyst on reaction rate and enantioselectivity of the aza-Piancatelli rearrangement.