Chiral enamides, cycloaddition

A series of chiral binaphthyl ligands in combination with AlMe3 has been used for the cycloaddition reaction of enamide aldehydes with Danishefsky s diene for the enantioselective synthesis of a chiral amino dihydroxy molecule [15]. The cycloaddition reaction, which was found to proceed via a Mukaiyama aldol condensation followed by a cyclization, gives the cycloaddition product in up to 60% yield and 78% ee. 

The use of chiral catalysts can result in asymmetric induction in [2 + 2] cycloadditions. The cycloaddition of ketene dimethyl thioacetal (44) with various enamides (43) in the presence of a chiral titanium(IV) catalyst, generated in situ, gives good yields of cyclobutanes 45 with high enantioselectivity.18... 

In 2010, Gong et al. reported a highly enantioselective three-component domino reaction, consisting of an enantioselective aza-Diels-Alder cycloaddition catalysed by a chiral phosphoric acid and a subsequent intramolecular hydroamination catalysed by a gold complex. The domino reaction occurred between aldehydes, an enamide, and 2-(2-propynyl)aniline... 

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