Three-Component Reactions of Diazoesters, Aldehydes, and Imines Using a Dual Catalytic System Consisting of a Rhodium(II) Complex and a Lewis Acid.

A dual catalytic system, dirhodium tetrapivalate/ytterbium(III) triflate, enables the three-component reactions of α-alkyl-α-diazoesters, aromatic aldehydes, and N-benzylidenebenzylamine derivatives to afford the corresponding β-amino alcohols in good yields after hydrolysis of the oxazolidine cycloadducts, whereas no β-amino alcohols are obtained in the absence of ytterbium(III) triflate. A similar dual catalytic system, dirhodium tetraacetate/ytterbium(III) triflate, is found to be effective in accelerating the reactions of α-aryl-α-diazoesters in high yields. Furthermore, the reactions using dimethyl diazomalonate are described.

Photochemically-induced C-C bond formation between tertiary amines and nitrones.

Photoexcited nitrones serve as excellent electron acceptors as well as radical acceptors in the presence of tertiary amines to give β-amino hydroxylamines via photochemically-induced direct sp(3) C-H functionalization of the tertiary amines. The combined use of an organophotosensitizer and photoirradiation was highly effective in accelerating addition reactions. Several nitrones and tertiary amines were successfully utilized to give β-amino hydroxylamines in good yield.