Direct Oxyamination Reaction of Aldehydes with Nitrosobenzene

Significance Palomo and co-workers present an α-oxyamination reaction of aldehydes using α,α-diphenylprolinol trimethylsilyl ether 1 as catalyst. The reaction was carried out with different aldehydes and nitrosobenzene; a subsequent reduction with sodium borohydride provided the corresponding N -hydroxy β-aminoalcohols. Long-chain aldehydes required 16 h at 20 °C to react (up to 75% yield and with er up to 99:1), whereas alkyl and aryl aldehydes only needed 5-30 minutes at 0 °C to room temperature (up to 70% yield and er up to 99:1). Another competing reaction of nitrosobenzene, namely α-aminoxylation of aldehydes, was not observed in any case.