N- and O-Alkylation of isoquinolin-1-ones in the Mitsunobu reaction: Development of potential drug delivery systems

Regioselective methods were investigated to prepare N- and O-alkylated isoquinolin-1-ones efficiently. The predicted regioselective alkylation of the nitrogen with (hetero)benzyl halides was complemented using (hetero)benzylic Mitsunobu electrophiles to alkylate predominantly at the oxygen. A series of drug-delivery conjugates was prepared demonstrating control over the site of alkylation. The Mitsunobu reaction provides a new approach to 1-alkoxyisoquinolines that were unavailable via previous harsher synthetic methods.