Michael addition desymmetric reactions

Chen et al. have further applied the TFA salt of 9-amino-9-deoxyepiquinine lo as chiral organocatalyst to the desymmetrization of prochiral a,a-dicyanoalkenes from 4-substituted cyclohexanones via domino Michael-Michael addition reactions with a, 3-unsaturated ketones. These reactions exhibited high synthetic efficacy and bicyclic products 16 with two new C—C bonds, and four stereogenic centers... 

Recently, an oxidative dearomatization of substituted phenols followed by a desymmetrizing asymmetric intramolecular Michael addition catalyzed by the pro-linol derivative 27 has been described towards the synthesis of highly functionalized polycyclic molecules with excellent enantioselectivities [40]. As shown in Scheme 2.15, the reaction starts with an oxidation of the phenol moiety to the corresponding mera-cyclohexadienones employing PhlCOAc), mild oxidant that does not react with the aldehyde nor with the catalyst. In the presence of different nucleophiles such as, methanol, cyanide, or fluoride, intermediates 26 are formed, which suffer intramolecular Michael addition of the aldehyde moiety to afford the desired chiral products 28 with excellent diastereo- and enantioselectivities. 

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