Visible‐Light‐Promoted Cascade Coupling of 2‐Isocyanonaphthalenes with Elemental Sulfur and Amines to Construct Naphtho[2,1‐d]thiazol‐2‐Amines

Abstract

A visible‐light‐induced strategy has been explored for the synthesis of naphtho[2,1‐d]thiazol‐2‐amines through ortho‐C‐H sulfuration of 2‐isocyanonaphthalenes with elemental sulfur and amines under external photocatalyst‐free conditions. This three‐component reaction, which utilizes elemental sulfur as the odorless sulfur source, molecular oxygen as the clean oxidant, and visible light as the clean energy source, provides a mild and efficient approach to construct a series of naphtho[2,1‐d]thiazol‐2‐amines. Preliminary mechanistic studies indicated that visible‐light‐promoted photoexcitation of reaction intermediates consisting of thioureas and DBU might be involved in this transformation.