Visible‐Light‐Promoted Cascade Coupling of 2‐Isocyanonaphthalenes with Elemental Sulfur and Amines to Construct Naphtho[2,1‐<i>d</i>]thiazol‐2‐Amines
Hongyu Ding, Siyu Shi, Yanan Hou, Wenxiu Cui, Rong Sun, Yufen Lv, Huilan Yue, Wei Wei, Dong Yi
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.