Mukaiyama/aldol domino reaction

Scheme 2.61. Syntnesis of (-)-panclicin D (2-258) and okinonellin B (2-261) employing the domino Mukaiyama aldol/lactonization reaction sequence.

Romo and coworkers [1] have extensively studied the domino Mukaiyama-aldol-lactonization reaction of aldehydes and thiopyridyl silyl S,0-ketene acetals,... 

Scheme 8.6 Domino Mukaiyama-aldol-Prins reaction of silyl enol ethers and unsaturated acetals [9].

The synthesis of aldehydes from alkenes known as hydroformylation using CO and hydrogen and a homogeneous catalyst is a very important industrial process [204]. Today, over seven million tons of oxoproducts are formed each year using this procedure, with the majority of butanal and butanol from propene. To further increase the efficiency of this process it can be combined with other transformations in a domino fashion. Eilbracht and coworkers [205] used a Mukaiyama aldol reaction as a second step, as shown for the substrate 6/2-63 which, after 3 days led to 6/2-65 in 91% yield via the primarily formed adduct 6/2-64 (Scheme 6/2.13). However, employing a reaction time of 20 h gave 6/2-64 as the main product. 

An interesting variation in this reaction combined an intermolecular Mukaiyama aldol followed by an intramolecular reaction (a domino Mukaiyama aldol) that gave cyclic conjugated ketone products.Borane derivatives such as C=C—OB(NMe2)2 react with aldehydes to give p-amino ketones. ... 

In 2013, another intramolecular hydrosilojqrlation was combined with a Mukaiyama aldol condensation by Gong et al. in an enantioselective relay catalytic cascade. This domino reaction occurred between atylacetylene silanols and glyoxylates and was induced by a combination of an achiral gold catalyst and a chiral N-triflyl phosphoramide. As shown in Scheme 7.37,... 

Scheme 7.37 Domino intramolecular hydrosilojgrlation-Mukaiyama aldol reaction catalysed by chiral phosphoramide catalysis and gold catalysis.

Scheme 2.7. Domino Mukaiyama/Michael/aldol reactions catalyzed by Sml2(THF)2.

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