Synthesis and reactivity of ruthenium amide-phosphine complexes. Facile conversion of a ruthenium amide to a ruthenium amine via dihydrogen activation and orthometalation. X-ray structure of RuCl(C6H4PPh2)[NH(SiMe2CH2PPh2)2]

Abstract

The reaction of LiN(SiMe2CH2PPh2)2 with RuCl2(PPh3)3 leads to the formation of the ruthenium amide complex RuCl(PPh3)[N(SiMe2CH2PPh2)2]. This complex reacts with H2 to form two isomeric amine-hydride derivatives of the formula RuCl(PPh3)H[NH(SiMe2CH2PPh2)2]. Reaction of RuCl(PPh3)[N-(SiMe2CH2PPh2)2] with MeLi, Me3SiCH2Li, or H2C=CHCH2MgCl does not lead to the expected hydrocarbyl derivative; rather, ortho metalation occurs to generate Ru(C6H4PPh2)[N(SiMe2CH2PPh2)2]. Attempts to displace the PPh3 ligand of RuCl(PPh3)[N(SiMe2CH2PPh2)2] with PEt3 lead to the formation of RuCl- (C6H4PPh2) [NH(SiMe2PPh2)2], having an amine ligand and the ortho-metalated phenyl group. The complex RuCl(C6H4PPh2)[NH(SiMe2CH2PPh2)2] crystallizes in space group P21/n with a = 9.8385 (5) A,b = 29.561 (1) A,c = 20.8665 (9) A, 8 = 101.683 (4)°, V = 5942.2 (5) A3, and Z = 4. Transformation of an amide linkage to an amide via H2 activation or ortho metalation is apparently driven by the formation of an intramolecular hydrogen bond between the amine hydrogen and the coordinated chloride; the N-H-Cl distance is 2.76 (6) A, which is shorter than the expected van der Waals separation of 3.0 Á.

Mechanisms of C–H bond activation: rich synergy between computation and experiment

“…For the nitrosyl species, SBM is slightly more accessible, while OA/RE is preferred with the anionic CO analogue. 34 The major geometric differences between the SBM transition state and OA/RE intermediate are in the C-W-C angles (40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50) • wider in the OA intermediate) and W ◊ ◊ ◊ H distances (ca. 0.1 Å shorter in the OA intermediate).…”

Catalytic Oxy‐Functionalization of Methane and Other Hydrocarbons: Fundamental Advancements and New Strategies

“…In related reactions, Fryzuk et al have reported dihydrogen activation across the chelating amido ligand of Ru(Cl)(PPh 3 )[N(SiMe 2 CH 2 PPh 2 ) 2 ], [108] and Morris et al have demonstrated that dihydrogen activation by a Ru II amido yields a complex in which the HÀH bond becomes protic-hydridic in character (i.e., H dÀ ···H d+ ). [109] Although H 2 activation by complex 1 is facile, complex 1 undergoes an intramolecular CÀH activaScheme 5.…”

Net Hydrogenation of Pt−NHPh Bond Is Catalyzed by Elemental Pt

“…5 Despite their importance, reports of well-defined reactions with late(r) transition metal systems are rare and mechanistic studies are limited. [5][6][7][8] Recently, C-H activation of hydrocarbons via net 1,2-addition of C-H bonds across metal-heteroatom bonds using late transition metals (with g6 d-electrons) bearing formally anionic ligands (e.g., -NHR or -OR) has been reported. [9][10][11][12][13][14] Despite interest in these C-H and H-H bond transformations, questions regarding the mechanism remain.…”

“…We initially presumed this straightforward pathway, which is consistent with the general notion of reactions with related systems. 5,7,8,13,19,20 Monitoring ( 1 H NMR) the reaction of 2 with H 2 and a plot of [2] versus time reveals an induction period ( Figure 2A). The observation of an induction period led us to consider Pt(s) as a heterogeneous catalyst.…”