TAMAO-FLEMING

Type I and II silicon-tethered carbonyl-ene reactions were first performed by Robertson.4,4a,4b One particularly striking application of this method is the conversion of isoserine derivative 3 (Scheme 1) into amino triol 4 via a carbonyl-ene reaction followed by Tamao-Fleming oxidation.5... 

Hunt and Roush <1995TL501> achieved a synthesis of swansonine 230 via a stereoselective allylation of a silyl allylboronate derived from tartaric acid followed by a Tamao-Fleming oxidation to introduce the C-2 hydroxy functionality (Scheme 54). 

This reaction, depending on the details of the reaction, is known as the Fleming Oxidation, the Fleming-Tamao Oxidation, the Tamao-Fleming Oxidation, or the Tamao-Kumada Oxidation. 

Despite the presence of two, relatively weak, N—O bonds ( 53 kcal/mol) (255) nitroso acetals are stable under neutral conditions. Therefore, a number of transformations can be performed on the periphery of the cycloadducts without effecting the nitroso acetal. These include both oxidation of alcohols, dihydroxyla-tion of alkenes (247,248,256), Tamao-Fleming type oxidation (248-250), reductions of ketones and esters (244,257-261), silylation and desilylation (247,257, 260), and activation with a variety of sulfonylating agents (247,248,257-260). 

This result dictated that any alkene-generating elimination process has to proceed via conditions not basic enough to enolize the tertiary amide. Using a procedure developed by Ochiai, the tetraalkylstannane unit of 119 was converted into the chlorotrialkylstannane of 121 in excellent yield. The formation of a halotin species enabled the use of the Tamao-Fleming oxidation36 for formation of the primary alcohol within 122. 

Like their carbon counterparts, silylcuprates and stannylcuprates readily participate in SN2 -substitution reaction with allylic electrophiles.43,51 For example, <37z//-diastereoselective allylic substitution of the vinyl oxiranes 147 with the lower-order cyanocuprate (PhMe2Si)Cu(CN)Li cleanly affords the allylsilanes 148 (Scheme 38).106 Products of this type can be converted into the corresponding diols with retention of configuration by Tamao-Fleming oxidation 53,53a,53b,107... 

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