Ruthenium silene complex

In 1988, Tilley and coworkers first succeeded in the synthesis of a ruthenium-silene complex by the reaction of Cp Ru(PR3)Cl with a Grignard reagent, and the structure was confirmed by X-ray crystallography (Eq. 9) [10]. They later synthesized an iridium complex in a similar manner (Eq. 10) [11]. Berry synthesized a tungsten-silene complex by treatment of a tungsten-chloride complex with Mg (Eq. 11) [12]. Although reactions of transition metal-silene complexes with Mel, HX, and MeOH have been reported, little is known about their reactivities [11,12]. 

Very recently, Berry and coworkers reported the formation of a ruthenium-silene complex from (PMe3)4RuHSiMe3 and BPh4, and they observed the interconversion between silene and a 16-electron ruthenium silyl complex (Eq. 12) [13a]. 

Hydrogenation of a ruthenium silene complex also involves oxidative addition and reductive elimination pathways , giving two hydride-containing products ... 

Reactions of the silene hydride complex Cp Ru(P(Pr-/)3)(I I)(r 2-C.I I2=SiPh2) with hydrosilanes proceed via an initial migration of the hydride to the silene ligand, affording as the final products either the disilyl hydride or the mono silyl dihydrido ruthenium(IV) complexes as described in Scheme 21. Similar reductive elimination and... 

Silene-transition metal complexes were proposed by Pannell121 for some iron and tungsten systems, and such species were observed spectroscopically by Wrighton.122,123 Thus intermediates such as 33 have been proposed in the preparation of carbosilane polymers from hydrosilanes,124 both as intermediates in the isotope scrambling observed to occur in similar ruthenium hydride systems125 126 and in the 5N2 addition of alkyllithium species to chlorovinylsilanes.47... 

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