The photoinduced pinacolisation of 4-oxo-4-phenylbutanamides 1 afforded 4,5-dihydroxy-4,5-diphenyloctanediamides 2 and 3 with unusual diastereoselectivities up to 83%, which depends on the amide substituent. In this reaction the solvent diethyl ether acts as a hydrogen donor. The structures of pinacols 2 and 3 were confirmed by X-ray analyses. Possible reasons for the diastereoselectivity and the preferred
Photocatalytic 1,2-oxo-alkylation reaction of styrenes with diazoacetates
作者:Fang Li、Siqi Zhu、Rene M. Koenigs
DOI:10.1039/d2cc02414d
日期:——
reactivity of diazoalkanes can be suppressed and a 1,2 oxo-alkylation reaction can be achieved (32 examples, up to 94% yield) without the formation of cyclopropane by-products via the formation of radical intermediates from ethyldiazoacetate.
Irradiation of 4-oxo-4-phenyl-butanoyl amines affords the corresponding delta-lactams via hydrogen abstraction from epsilon-position. Remarkable diastereoselectivities up to > 99% are obtained. (C) 1998 Elsevier Science Ltd. All rights reserved.