Design and Synthesis of a [2.2]Paracyclophane‐based Planar Chiral Dirhodium Catalyst and its Applications in Cyclopropanation Reaction of Vinylarenes with α‐Methyl‐α‐Diazo Esters

Christoph Zippel, Zahid Hassan, Martin Nieger, Stefan Bräse
2020
A planar chiral dirhodium paddlewheel complex Rh$_{2}$(S $_{p}$−PCP)$_{4}$ based on the [2.2]paracyclophane has been synthesized for the challenging cyclopropanation of venylarene derivatives with tert‐butyl α‐diazo propionates. The homobimetallic rhodium catalyst relies on the high steric demand and rigidity of [2.2]paracyclophane that favors the cyclopropanation of 1‐aryl substituted, 1,1‐disubstituted and benzannulated alkenes over β‐hydride migration at room temperature with high diastereoselectivity.
doi:10.5445/ir/1000122660 fatcat:twino3hw5rdwvntqo24bb5nylq