Bis-phosphine allene ligand: coordination chemistry and preliminary applications in catalysis

Abstract

A 1,3-bis-diphenylphosphine allene can give rise to new coordination complexes with palladium, platinum and gold metals. These complexes were fully characterized by NMR, HRMS and X-ray diffraction analysis. For gold(i), the corresponding dinuclear complex has been used in a series of diagnostic catalytic reactions and gave promising preliminary results in asymmetric catalysis.

Allene-derived gold and platinum complexes: synthesis and first applications in catalysis

“…For example, bisphosphine allene ligands have been reported in 1:1 (ligand to metal) complexes with Rh(I), 2 Pd(II) and Pt(II). 3 Complexes of bis-phosphine allene ligands with Au(I) gave 1:2 or polymeric complexes. 3 Pyridines in general constitute one of the most established and well performing classes of ligands for transition metal complexes, but their use in allene-containing ligands is limited.…”

“…3 Complexes of bis-phosphine allene ligands with Au(I) gave 1:2 or polymeric complexes. 3 Pyridines in general constitute one of the most established and well performing classes of ligands for transition metal complexes, but their use in allene-containing ligands is limited. There is one reported example of bis(pyridyl)allene-metal complex in a 1:1 complex with Cu(I) (detected by 1 H NMR, Figure 1) and a 2:2 complex was crystallised with Ag(I).…”

“…4 In all of these complexes, the allenic structure shows carbene character at the central carbon (as bent allenes) 5 but retains its chemical integrity. However, very few catalytic reactions have been reported with some of these allene-metal complexes, 2,3,6 and progress in this field is slow, probably due to the ability of metals to activate the allene 1,7 towards nucleophilic attack, 8 which disrupts the allene backbone. In this context, Fensterbank et al reported in 2015 the reaction of allenes containing a pyridine and a phosphine oxide substituents with Au(I) complexes to give Au(I)-carbene-type complexes from the nucleophilic attack of the pyridine into the allene (Figure 1, bottom).…”

Recent Advances in the Development of Chiral Gold Complexes for Catalytic Asymmetric Catalysis

“…In 2016, Mouries‐Mansuy and Fensterbank [24] developed a new type of bis‐phosphine allene ligands, which are capable of coordinating to transition metals including Pd, Pt and Au. The racemic bis‐phosphine allene digold(I) complex was stable enough to be resolved to the enantiomers by chiral HPLC.…”

Copper Hydride Catalyzed Enantioselective Synthesis of Axially Chiral 1,3-Disubstituted Allenes

“…3 Finally, chiral allenes have also been explored in asymmetric autocatalysis and as ligands for the development of enantioselective transformations. 4−6…”