Keto esters domino Michael additions

This catalyst was also used by Ma et al. to promote a domino Michael addition-cyclisation process of aldehydes with a-keto-a,p-unsaturated esters, proceeding smoothly in water in the presence of AcOH as an additive.The corresponding chiral cyclic hemiacetals were formed in both high yields and diastereoselectivities and almost complete enantioselectivities, and were subsequently oxidised by treatment with PCC to furnish highly functionalised 3,4,5,6-tetrasubstituted dihydropyrones (Scheme 1.34). 

This catalyst was involved in the development of a new asymmetric orga-nocatalytic domino reaction of a,p-unsaturated aldehydes and p-keto esters following a Michael addition-Morita-Baylis-Hillman mechanism." As shown in Scheme 1.38, the formed cyclohexenone products were obtained in moderate to good yields and with high stereoselectivities for a wide range of substrates. 

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