Sequential Oxidative Fragmentation and Skeletal Rearrangement of Peroxides for the Synthesis of Quinazolinone Derivatives

For the first time, the sequential reaction of peroxyoxindole that
involves base-promoted oxidative fragmentation to isocyanate formation
and primary amine or amino alcohol accelerated skeletal rearrangement
to synthesize exo-olefinic-substituted quinazolinone or oxazoloquinazolinone
is reported. The advantages of this new reaction include a broad substrate
scope and transition-metal-free and room-temperature conditions. The
formation of the isocyanate as a key intermediate that accelerates
oxidative skeletal rearrangement has been confirmed by trapping experiments
and spectroscopic evidence.