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Diphenylprolinol silyl ether was found to be an effective organocatalyst in the enantioselective and direct Michael reaction of nitroethanol and alpha,beta-unsaturated aldehydes, affording the 1-hydroxy-trans-3,4-disubstituted tetrahydropyrans after isomerization. The generated Michael addition products are useful synthetic intermediates, which can be converted into chiral tetrahydropyran with a quaternary stereocenter, 3-substituted cis- and trans-prolines, and alpha-amino acid derivatives.

Diphenylprolinol silyl ether was found to catalyze the formal carbo [3 + 3] cycloaddition reaction through the domino reaction via the Michael reaction, followed by Knoevenagel condensation of the alpha,beta-unsaturated aldehyde and dimethyl 3-oxopentanedioate, affording substituted cyclohexenone derivatives with excellent enantioselectivity.

Compounds comprising a diaryl ether skeleton exist among natural phenols. The diaryl ether skeleton is thought to be biosynthesized through the coupling of two or more phenols. It is an important structural feature in medicines and agrochemicals, and it is imperative to develop methods for constructing such skeletons in organic synthesis. However, by the synthesis method through the coupling of phenols, coupling occurs preferentially at the ortho-substituted carbon atom of phenols. In this study, various radical-generating reagents and conditions were investigated with the aim of developing a short-step construction method of the diaryl ether skeleton by the radical homo-coupling of two phenol molecules. In addition, cross-coupling reactions between radicals of 2,4,6-tri- tert -butylphenol and p-substituted phenol were conducted to synthesize eight C (ortho)–O coupling products. Based on the results, a computational chemical approach was employed to verify the cause of C (ortho)–O bond formation. Image 1 [ABSTRACT FROM AUTHOR]

Diphenylprolinol silyl ether was found to promote asymmetric, catalytic and direct α-benzoyloxylation of aldehydes with benzoyl peroxide to afford oxidized products in good yields with excellent enantioselectivity. [ABSTRACT FROM AUTHOR]

Review: 93 refs. [ABSTRACT FROM AUTHOR]