Synthesis of alkaloids from amino acids via N-acyliminium ions generated by one-pot radical decarboxylation–oxidation
作者:Alicia Boto、Rosendo Hernández、Ernesto Suárez
DOI:10.1016/s0040-4039(00)00306-3
日期:2000.4
A one-pot methodology for the synthesis of α-substituted nitrogen heterocycles from commercial amino acids has been developed. Good stereoselectivity can be achieved with chiral substituted rings. This procedure has been applied to the synthesis of piperidine, pyrrolidine and indolizidinone alkaloids.
The addition of 2-tert-butyldimethylsilyloxyfuran to cyclic N-acyliminium ions containing cyclohexyl-based chiral auxiliaries
作者:Marcelo G.M D'Oca、Ronaldo A Pilli、Ivo Vencato
DOI:10.1016/s0040-4039(00)01749-4
日期:2000.12
addition of silyloxyfuran 5 to chiral five- and six-membered N-acyliminium ions derived from 3/4a,b occurred exclusively through the addition to the N-acyliminium Si face to provide threo-6/7a,b as the major isomer (73–84% yield, 2:1–7:1 diastereoisomeric ratio) which were converted to the corresponding bicyclic lactams 10 and 11 with efficient recovery of the chiralauxiliary.