LEY GRIFFITH Oxidation reagent

LEY - GRIFFITH Oxidation reagent Oxidation ol alcotwls to caitxnyl compounds with a pemjthenate catalyst and N-methylmorpholine - N-oxIde (NMO), In the presence of other functional gmups... 

LEY GRIFFITH Oxidation reagent Oxidation of alcohols to caitxsnyl compounds with a pemithenate catalyst and N-methylmofphoHne - N-oxide (NMO), in the presence of other functional groups... 

Oxidation of the alcohol 10-[3 -methoxy-2 -(methoxymethoxy)phenyl]decan-l-ol (7.19) with TPAP [(C3H7)4NRu04] afforded the aldehyde 10-[3 -methoxy-2 -(methoxymethoxy)phenyl] decan-1-al (7.20) in quantitative yield. The reagent TPAP is known as Ley-Griffith s reagent. 

Griffith, W., S. Ley, G. Whitcombe, and A. White (1987) Preparation and use of tetra-n-butylammonium per-ruthenate (TBAP reagent) and tetra-n-propylammonium per-ruthenate (TpAP reagent) as new catalytic oxidants for alcohols. Chemical Communications, 1625-1627. 

There are problems associated with the expensive disposal of toxic waste from metal-based oxidations of alcohols. Thus, the focus has been largely on catalytic reactions as typified by Ley and Griffith s tetrapropylammonium perruthenate oxidant (section 7.1.6). Completely metal-free oxidations have much potential for environment-friendly oxidations, particularly if the reagent can be recovered and recycled. The most common metal-free oxidation of alcohols are TEMPO/oxone or TEMPO/N-chlorosuccinimide oxidation, Dess-Martin periodane oxidation (section 7.1.5) and Swern oxidation (section 7.1.4) and its several variants. 

Discovered in 1987, the tetra-n-propylammonium perruthenate (TPAP) oxidation is straightforward to run. The reagent is expensive and thus it is used in catalytic amounts and becomes re-oxidized by A-methyl morpholine-A-oxide. For a review see Ley, S. V. Norman, J. Griffith, W. P Marsden, S. P. Synthesis 1994, 639-666. 

The TPAP oxidation developed by Griffith and Ley [41] has proven to be a very important tool in organic synthesis. The polymer-supported perruthenate (PSP) version, first developed in the Ley group [42], enables the use of the reagent either stoichiometrically or catalytically in tandem with a co-oxidant. The power of PSP... 

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