Imidate–Phosphanes as Highly Versatile N,P Ligands and Their Application in Palladium‐Catalyzed Asymmetric Allylic Alkylation Reactions

Abstract

Chiral imidate–phosphanes were developed as a new type of N,P ligands. These ligands are easily accessible through a one‐step procedure starting from a commercially available chiral aminophosphane and an imidate precursor. Excellent performance of the catalyst system was observed with various carbon nucleophiles in the Pd0‐catalyzed asymmetric allylic alkylation (up to 99 % yield and >99 % ee). Moreover, good to excellent enantioselectivities could also be obtained in the allylic alkylation of more difficult linear unhindered substrates and cyclic substrates, demonstrating that this new catalyst system has a broad substrate scope.

Ferrocene-derived P,N ligands: synthesis and application in enantioselective catalysis

“…Noël and Van der Eycken have developed the imidate/ phosphane based ferrocenyl ligand 42 as a new type of P,N-ferrocenyl ligand [59,60]. These ligands showed very high enantioselectivities in the allylic alkylation of the linear sterically hindered substrate 20, with a wide variety of carbon nucleophiles (Scheme 11).…”

Cytisine as a scaffold for ortho-diphenylphosphinobenzenecarboxamide ligands for Pd-catalyzed asymmetric allylic alkylation

“…Generally, the influence of the base additive in the BSA/base system is difficult to elucidate and it depends on the individual catalytic system [13f]. However, a similar pronounced BSA/activator effect has been observed in the Pd-catalyzed AAA in the presence of C 2 -symmetric ferrocene diphosphine-disulfone [24] as well as with imidate-phosphine ligands [25]. Switching the ligand to tetrahydrodeoxocytisine derived 7, containing additional amino group, dropped the enantioselectivity remarkably.…”

Palladium‐Catalyzed Enantioselective Allylic Substitution in the Presence of Monodentate Furanoside Phosphoramidites

“…16 % ee ${[\alpha ]_{\rm{D}}^{20} }$ =−10.2 ( c =1.0, CHCl 3 ), [ lit 20. ${[\alpha ]_{\rm{D}}^{20} }$ =−25.1 ( c =1.1, CHCl 3 ), 74 % ee ( S )].…”