Planar-chiral imidazole-based phosphine ligands derived from [2.2]paracyclophane

Abstract

Two planar chiral heteroaryl monophosphines have been synthesised and studied. The phosphines are readily prepared from 4-imidazole[2.2]paracyclophane by selective deprotonation and reaction with the appropriate dialkylchlorophosphines. The planar chiral imidazole was constructed in four steps from readily available [2.2]paracyclophane. The 2-phosphino-N-[2.2]paracyclophanes were active in the Suzuki–Miyaura coupling of aryl bromides and chlorides. Coordination studies indicate P,N-chelation in the solid-state. These studies lay the foundations for asymmetric couplings.