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Active methylene compounds such as nitroalkanes (Eq. 1.19), malonates, and β‐keto esters are suitable Michael donors in the Michael reaction using α,β‐unsaturated aldehydes as a Michael acceptor, catalyzed by diphenylprolinol silyl ether catalyst [42].

Oximes, such as benzaldehyde oxime, also act as suitable Michael donors to afford β‐hydroxy carbonyl compounds after hydrogenolysis (Eq. 1.20) [43]. Given that asymmetric oxy‐Michael reactions are difficult because of the facile retro‐Michael reaction, this two‐step reaction is synthetically useful.

Thiol is also a good Michael donor and chiral β‐thio aldehydes were obtained with excellent enantioselectivity [44].

Aza‐Michael reactions were also reported using thiazoles, tetrazoles, and succinimides, and the products were generated with excellent enantioselectivity [45].

Construction of a C–P bond by the Michael reaction was reported. Asymmetric hydrophosphination proceeded by a reaction of diphenylphosphine and α,β‐unsaturated aldehydes catalyzed by diarylprolinol silyl ether (Eq. 1.21) [46].

(1.19)

(1.20)

(1.21)

Nonactivated ketones such as cyclohexanone are also employed as Michael donors in the reaction of α,β‐unsaturated aldehydes catalyzed by a combination of diphenylprolinol silyl ether and hydroxyproline (or pyrrolidine), to afford the Michael products with excellent enantioselectivity (Eq. 1.22) [47]. The key nucleophile is not an enamine but an enolate, which is generated from a secondary amine by combination with p‐nitrophenol (Eq. 1.23) [48].

(1.22)

(1.23)