Asymmetric Synthesis of Palladacycles by Regioselective Oxidative Cyclization of <i>C</i>₂-Symmetrical, Chiral Alkenes and Determination of the Configuration of All Stereocenters

Abstract

The reaction of Pd2(dba)3·CHCl3 with 2 equiv of chiral, C2-symmetrical cyclopropenes bearing lactate esters at the 1- and 2-positions provided trans-5-palladatricyclo[4.1.0.02,4]heptanes (PTHs) in high diastereomeric excess. The configuration of all stereocenters in the major diastereomer was determined by X-ray structure analyses of the complexes of the PTH with norbornadiene; the C2 symmetry of the (+)-DIOP complex of the minor diastereomer proves that this was also a trans isomer