Light fluorous catalysts

As chemical synthesis moves from discovery to production, scales increase and the use of catalytic rather than stoichiometric quantities of reagents is increasingly advantageous from both the economic and environmental standpoints. The vast majority of fluorous catalysts prepared to date are best classified as heavy fluorous catalysts, and they are removed from the reaction mixture by liquid/liquid separation techniques. On the one hand, fluorous silica gel provides another option for these catalysts, which is to use a solid/liquid separation instead. On the other hand, fluorous silica gel enables the use of light fluorous catalysts, such as the palladium catalyst shown in Scheme 36. Mizoroki-Heck reactions are promoted by standard conductive heating (oil bath) or microwave heating. After cooling and solid-phase extraction. 

Curran, D. P. (2006) Organic synthesis with light-fluorous reagents, reactants, catalysts, and... 

Stuart and co-workers reported the first synthesis of a light fluorous BINAP, (R)-6,6 -bis(lH,lH,2H,2H-perfluorooctyl)-2,2 -bis(diphenylphosphino)-l,l -bi-naphthyl (F content = 38%), and its application to a Ru complex catalyzed asymmetric hydrogenation of dimethyl itaconate [Eq. (2)] [10). The reaction was carried out at ambient temperature under the same reaction conditions as those reported by Noyori [11). The chemical yield (83%) and enantioselectivity (95.7% ee) were similar to those reported (88% and 95.4% ee, respectively). However, there was no description of the recovery of the catalyst or ligand. 

Matsugi M, Curran DP (2005) Synthesis, reaction, and recycle of light fluorous Grubbs-Hoveyda catalysts for aUcene metathesis. J Org Chem 70 1636-1642... 

The introduction and subsequent commercialization of fluorous silica gel have enabled the light branch of fluorous chemistry. The applicability of this chemistry covers all types of reaction components (substrates, reagents, reactants, catalysts, scavengers) and cuts across the synthesis spectrum from small-scale discovery... 

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