Base-promoted ring-opening/recyclization of naphthoquinones to access benzo[5,6][1,4]thiazino[4,3-b]isoquinoline-7,12-diones at room temperature

Abstract

A base-promoted nitrogen atom insertion into naphthoquinone rings to construct N-heterocycles has been described. This approach starts from easily available 2-aminobenzenethiols and 2-(indol-3-yl)naphthoquinones, affording a series of structurally valuable polycyclic heterocycles in satisfactory yields at room temperature under transition-metal-free conditions. Mechanism studies indicate that indolyl is essential for this transformation, which mediates the ring-opening and rearrangement of naphthoquinone rings.