Synthesis, coordination chemistry, and metal complex reactivity of (dimethylamino)methyl-substituted triarylphosphanes; X-ray study on [AuCl(PPh3−nArn)] (Ar=1-C6H3(CH2NMe2)2-3,5, n=1, 3; Ar=1-C6H4(CH2NMe2)-4, n=3)

Abstract

The synthesis of the first series of 4-mono and 3,5-bis(dimethylamino)methyl-functionalized triarylphosphanes of the general formula PPh 3 À n Ar n (Ar = 1-C 6 H 3 (CH 2 NMe 2 ) 2 -3,5 (NC(H)N), n = 1 (ligand 2) or n = 3 (ligand 4); Ar = 1-C 6 H 4 (CH 2 NMe 2 )-4 (NC(H)), n = 3 (ligand 7)) is described. These phosphanes were used for the construction of complexes of the form [AuCl(P)] and [PtCl 2 (P) 2 ]. In these complexes selective coordination of phosphorus to the metal ion is observed. The 31 P NMR data show the formation of cis-Pt complexes, even in the case of triarylphosphane 4, which features a tris{3,5-bis(dimethylamino)methyl} substitution pattern. The structure of the gold complex of mono-3,5-functionalized triarylphosphane 2 in the solid state shows a striking resemblance to the structure of the corresponding complex [AuCl(PPh 3 )]. The solid-state structure of the AuCl complex of tris-4-functionalized ligand 7 differs from that of [AuCl(PPh 3 )] in the sign of the torsion angles. The amine functionalities in this class of gold compounds could be reacted selectively with either acid (HCl, H 3 PO 4 ) to generate ammonium salts or with an alkylating agent (benzyl bromide) to afford benzyl ammonium salts, without the violation of the Au-P bond.

Structure–Activity Relationships of Oligocationic, Ammonium‐Functionalized Triarylphosphines as Ligands in the Pd‐Catalyzed Suzuki–Miyaura Reaction

“…Lithiation of 11 and subsequent reaction with PBr 3 then yielded the neutral tris(3,5‐bis[(benzylmethylamino)methyl]phenyl)phosphine ( 12 ). Previously reported tris(3,5‐bis[(dimethylamino)methyl]phenyl)phosphine ( 13 )9 is a smaller analogue of this neutral ligand. These synthetic efforts have provided us with a series of triarylphosphine ligands that differ in size and charge.…”

Coulombic inter-ligand repulsion effects on the Pt(ii) coordination chemistry of oligocationic, ammonium-functionalized triarylphosphines

“…Next to the hexacationic Dendriphos ligands, di-, tri and tetra-ammoniomethyl functionialized [5] 4+ , [6] 2+ and [7] 3+ have been developed. 9d Hexa-aminomethyl functionalized 3 14 and 4 9d were designed as neutral, sterically similar analogues of [1] 6+ and [2] 6+ . Here, we turn our attention to the reactivity of this series of oligocationic ligands, as well as their neutral analogues 3 and 4, with respect to Pt(II) ions and present investigations concerning the role that repulsive Coulombic interactions play in their coordination behaviour.…”

Fast Suzuki–Miyaura Cross‐Coupling Reaction with Hexacationic Triarylphosphine Bn‐Dendriphos as Ligand

“…The results for 1 and 2 are in line with the molecular modelling and coordination experiments on these ligands, reported elsewhere. [1,16] Based on these studies we predicted enlarged cone angles and a bulky behaviour for 2. We (1) at 0.01 mol % Pd loading using Bn-Dendriphos.…”

“…PdA C H T U N G T R E N N U N G (dba) 2 , [17] PA C H T U N G T R E N N U N G (NCN) 3 (1), [16] and Bn-Dendriphos (2) [1] were prepared according to previously reported procedures. Aryl bromides and arylboronic acids were obtained from Acros Chimica and used without further purification.…”