Ruthenium-catalysed reactions phosphine complexes

Carbon dioxide in its supercritical state is a reaction medium of great interest. Noyori et. al. recently detected that Ruthenium(II)-phosphine-complexes of typ [(X)2Ru(PMe3)4] 15 (X = H) and 16 (X = Cl) can act as highly active catalysts for an effective transition metal catalysed hydrogenation of CO2 to formic acid in a supercritical mixture of CO, H, and NEt, without use of any further solvent. 

Remarkably, the heterogenisadon process can confer dramatically enhanced activity on the metal complex. Thus, the dimolybdenum complex [Mo2(MeCN)8][BF4]-Si02 prepared by direct reaction of silica with the metal complex is unusual in its ability to catalyse the polymerisation of norbomene in the absence of an aluminium co-catalyst and at moderate temperatures.165 Sol-gel processing of the ruthenium complex m-Cl(H)Ru(CO)(P)3 (where P is a coordinated ether-phosphine) with tetraethoxysilane and [Al(0-i-Pr)3] gives a stable material with moderate surface area which is active in the hydrogenation of fraras-crotylaldehyde with reasonable chemoselectivity to the carbonyl reduced products, cis- and trans-crotyl alcohol.166... 

The mechanism of the Arbuzov rearrangement of (allyloxy)phosphines PhJP-(0C3H5)34 (n = 0-2) at room temperature catalysed by [CpRu(AN>3]PF4 has been investigated. A new procedure has been developed for the preparation of enantiomerically pure sulphoxides and ruthenium complexes such as [CpRu((X>)(FI%3)(t-BuMeSO)]SbF4 by a combination of asymmetric oxidations of dialkylsulphides and metal resolution of the products. The Diels Alder reaction of coordinated dienophiles in [CpRu(dnq]p)3 (dienophile)JPF( have been investigated for a range of complexes. ... 

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