Visible‐Light‐Initiated Cascade Reaction of 2‐Isothiocyanatonaphthalenes and Amines under Additive‐ and External Photocatalyst‐Free and Mild Conditions

Abstract

A simple and efficient visible‐light‐initiated cascade reaction of 2‐isothiocyanatonaphthalenes and amines with ambient dioxygen as the sole oxidant under additive‐, external photocatalyst‐free and ambient conditions was developed. 38 Examples of N‐substituted naphtho[2,1‐d]thiazol‐2‐amines were regioselectively constructed in good to excellent yields.

Metal‐Free Synthesis of 2‐Aminobenzothiazoles via I2‐Catalyzed Tandem Cyclization Reaction of Amines and Carbon Disulfide

“…(iii) Tandem cyclization reactions of isothiocyanates with 2‐substituted anilines, or amines. [ 11‐12 ] This kind of methodology involves constructing both C—S and C—N bonds in one pot. Besides, synthesizing 2‐aminobenzothiazoles via three‐component tandem reactions of 2‐substituted anilines, carbon disulfide (CS 2 ), and amines has attracted increasing attention from the view point of atom economy and operational simplicity.…”

Light‐Induced Domino and Multicomponent Reactions: How to Reach Molecular Complexity without a Catalyst

“…[61] They were prepared through a visible light-assisted, additiveand photocatalyst-free cascade reaction, starting from 2isothiocyanatonaphthalenes 87 and primary or secondary amines 88, under oxygen atmosphere (Scheme 32). [62] It was deduced that the isothiocyanate 87 completely converted after 6 hours, by monitoring the reaction as a function of time, via 1 H-NMR. The reaction proceeds with the immediate formation of a certain amount of 89 together with thiourea a obtained by the nucleophilic addition of the amine's nitrogen to the isothiocyanate's carbon.…”

Electro-oxidative three-component cascade coupling of isocyanides with elemental sulfur and amines for the synthesis of 2-aminobenzothiazoles

“…For example, Fan and Zhang's group disclosed an I 2 -catalyzed and oxygen-promoted cascade reaction of isothiocyanates with amines at high temperatures (Scheme 1a). 7 Both Yang's group 8 and He's group 9 developed a photochemical coupling of 2-isothiocyanatonaphthalenes with amines under an oxygen atmosphere in 2020 (Scheme 1b). Lei's group reported an electrochemical synthesis of 2-aminobenzothiazoles through the direct combination of aryl isothiocyanates with secondary aliphatic amines (Scheme 1c).…”