Conformational Preferences Driven by theC-Methyl Substituent in Chelatedo-Diphenylphosphino-α-methyl-N,N-dimethylbenzylamine Rhodium Complexes

Abstract

The stereochemistry of the chelate rings of a number of rhodium aminophosphine complexes is studied by NMR spectroscopy. The similarity in the variable-temperature behavior for the different compounds is consistent with them having in common highly preferred chelate ring conformations. The six-membered metallacycle of coordinated (R)-PN (PN = o-diphenylphosphino-alpha-methyl-N,N-dimethylbenzylamine) adopts a delta conformation in the solid state. NMR experiments indicate that this conformation is strongly favored in solution as well. The preferred sense of helicity is imposed by the absolute configuration of the stereogenic carbon atom on the ligand, which exerts an important steric control. The complex [Rh(TFB)((C(6)H(4)CHMeNMe(2))(2)P(C(6)H(4)CHMeNHMe(2)))](BF(4))(2).H(2)O.Me(2)CO crystallizes in the monoclinic space group P2(1) with a = 12.0548(11) A, b = 16.139(2) A, c = 12.1804(10) A, beta = 100.742(9) degrees, Z = 4.

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)

“…Furthermore, many examples apply increased steric bulk on the phenyl fragments thus rendering the ligands suitable candidates for high turnover C-C, C-N, or C-O coupling reactions [4]. The functionalization of arylphosphanes with potentially ligating groups opened up a new field of research, leading the way for secondary (ligand-to-metal) interactions or the formation of mixed metal complexes [5]. Examples of such ligands are the 2,6-bis(dimethylamino)methyl-substituted arylphosphanes ( Fig.…”

In Situ Generation of ArCu from CuF2 Makes Coupling of Bulky Aryl Silanes Feasible and Highly Efficient

“…Unless specified otherwise, all compounds used were purchased from commercial sources and used without further purification. Compounds 3 , 8 , [PdCl 2 (IDM) 2 ], [PdCl 2 (AsPh 3 )(IDM)], 4 , PEPPSI, trans‐ [Pd(C 6 F 5 )(Br)(PPh 3 ) 2 ], trans‐ [Pd(C 6 H 4 CF 3 )(I)(PPh 3 ) 2 ], trans‐ [Pd(C 6 H 4 CF 3 )(F)(PPh 3 ) 2 ], [CuF 2 (bipy)] ⋅ 3 H 2 O (bipy=2,2′‐bipyridine), Cl−Si(OEt) 3 , and 1‐[2‐(diphenylphosphino)phenyl]‐ N , N ‐dimethylmethanamine were made by methods reported in the literature. Particularly, anhydrous CuF 2 was purchased from Alfa Aesar, Ph−Si(OEt) 3 was purchased from Aldrich, and (C 6 F 5 )Si(OEt) 3 from Fluorochem.…”

Bis[2-(morpholinomethyl)phenyl]phenylphosphane

“…For related structures, see Chuit et al (1993); Copolovici, et al (2007); Copolovici, Silvestru, Isaia et al (2008); . For the use of phosphines containing organic groups with pendant arms as ligands in the coordination chemistry, see Alonso et al (2003), Brammer et al (2000), de Graaf et al (1988), Kapteijn et al (1996), Fierro-Arias et al (2005), Pfeiffer et al (2000)]. For van der Waals radii, see: Emsley (1994).…”

“…Phosphines containing organic groups with pendant arms, e.g. PPh n [C 6 H 4 (CH 2 NMe 2 )-2] 3-n , were successfully used as ligands in the coordination chemistry of various transition metals [Co (Brammer et al, 2000), Rh (Alonso et al, 2003), Pd (de Graaf et al, 1988;Kapteijn et al, 1996;Fierro-Arias et al, 2005), Pt (Pfeiffer et al, 2000)]. In order to extend this class of potential phosphine ligands we decided to investigate other related compounds and here we report on the…”