An Unusual Polyheterocyclic Diversity by the π-Cyclisation of N-Carbamoyliminium Ion, with or without Tandem N,N-Acetal Cleavage, from Spiro(imidazolidinoquinazolinones)
An Unusual Polyheterocyclic Diversity by the π-Cyclisation of <i>N</i>-Carbamoyliminium Ion, with or without Tandem <i>N</i>,<i>N</i>-Acetal Cleavage, from Spiro(imidazolidinoquinazolinones)
作者:Adam Daïch、Anthony Pesquet、Servane Coste、Luc Van Hijfte
DOI:10.1055/s-2008-1067032
日期:2008.5
Spiro(imidazolidinoquinazolinones), obtained easily in one step from 1-carbamoylisatins, are readily converted in three steps by successive N-alkylations and sodium borohydride regioselective reduction into the corresponding hydroxyspirolactams. The latter are valuable platforms for further transformations via the intermediacy of N-acyliminium species and have been applied to the synthesis of original isoquinoloquinazoline, indoloquinazoline and imidazoindole derivatives.