Abstract:
A facile and efficient method for the diastereo/regioselective synthesis of highly functionalized spiro-oxetane
oxindoles has been described. The 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed reaction proceeds via spiro-annulation of
isatins and allenoates. The reaction is compatible with a wide range of isatins containing electron-donating groups (EDGs) and
electron-withdrawing groups (EWGs) with various allenoates affording the corresponding products in acceptable yields. It is
noteworthy that this is the first protocol for constructing structurally diverse motifs of highly functionalized spiro-oxetane oxindoles
of pharmaceutical relevance.
