31P n.m.r. study of tertiary phosphine complexes of gold(I)

Homogeneous gold-catalyzed hydrosilylation of aldehydes

“…It has been reported that while the reaction [Et 4 N][AuBr 2 ] with 1 or 2 equiv. of PBu 3 leads to the formation of [AuBr(PBu 3 )] or [Au(PBu 3 ) 2 ]Br, respectively, higher PBu 3 concentrations result in a rapidly exchanging [Au(PBu 3 ) 3 ]Br species even at À120°C [5]. We have observed a similar behavior at room temperature during the titration of [AuCl(tht)] with various amounts of PBu 3 by 31 P NMR (Fig.…”

“…Although the formation of a tri-coordinated AuHP 2 intermediate was proposed for [AuCl(xantphos)]-catalyzed dehydrogenative silylation of alcohols [8], the formation of a mononuclear species with PBu 3 seems unlikely. The increasing amount of 4 with respect to gold should increase the level of substitution [5] and thus the rate of the oxidative addition of the hydrosilane should decrease (Scheme 1) resulting in a proportionally slower catalytic reaction. Since the opposite effect was observed, an alternative mechanism must be operational.…”

[Au2Cl2(fdpp)3], a Structural Intermediate in the Assembly of Gold–Phosphine Chain Polymers

“…In fact, the product is a multi-molecular spccics containing a complex ion with the structural formula [Au_,-Cl2(fdpp)3], (1). The 2:3 gold:ligand ratio of this complex highlights the documented fact that in Au ~ chemistry the material isolated in the solid state is not necessarily the same as the predominant species observed in solution (Colburn, Hill, McAuliffe & Parish, 1979 Previously reported AuCIP~ structures (where P is a phosphine) have been described as displaying coordination geometries intermediate between idealized three-and fourfold (Jones, 1981(Jones, , 1983. However, the Au..-C1 distances in these structures are considerably shorter than in (1).…”

The Chemistry of Gold

“…It was first demonstrated by 31 3 or P(OCH 2 ) 3 CEt finally the two-three-and four-coordinated species are observed [180][181][182]. It was first demonstrated by 31 3 or P(OCH 2 ) 3 CEt finally the two-three-and four-coordinated species are observed [180][181][182].…”