Copper(I)‐Catalyzed Cascade Synthesis of 2‐Substituted 1,3‐Benzothiazoles: Direct Access to Benzothiazolones

Abstract

An efficient cascade process for the preparation of 2‐substituted 1,3‐benzothiazoles directly from 2‐haloaryl isothiocyanates and O or S nucleophiles by a Cu‐catalyzed, intramolecular, C–S bond formation has been developed. This cascade method is viable for the efficient syntheses of both O‐ and S‐substituted 1,3‐benzothiazoles. Furthermore, 1,3‐benzothiazol‐2(3H)‐ones having an alkyl group allow easy access to 1,3‐benzothiazolones. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Azole‐Anion‐Based Aprotic Ionic Liquids: Functional Solvents for Atmospheric CO2 Transformation into Various Heterocyclic Compounds

“…Moreover, various ortho ‐phenylenediamines with electron‐donating as well as electron‐withdrawing substituents could be converted into their corresponding 2‐benzimidazolones in moderate‐to‐high yields, whilst their activities were comparable to those of [TBA] 2 WO 4 ‐catalyzed carbonylation reactions . In addition, with [Bu 4 P][2‐MIm] as both the catalyst and the solvent, 2‐aminothiophenol reacted with atmospheric CO 2 to produce benzothiazoline (Table ), which is ubiquitous in the scaffolds of pharmacologically active agents and natural products …”

“…[2a] In addition, with [Bu 4 P][2-MIm] as both the catalysta nd the solvent, 2-aminothiophenol reacted with at-mosphericC O 2 to produce benzothiazoline (Table 4), which is ubiquitous in the scaffolds of pharmacologically activea gents and naturalp roducts. [12] Scheme2.Possiblep athway for the reaction of propargylic alcohols with CO 2 ,catalyzed by [Bu 4 P][2-MIm].…”

Development of Divergent Synthetic Methods of Pyrimidobenzothiazine and Related Tricyclic Heterocycles

“…With these findings [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53], the author investigated the transition-metal (Pd, Cu, Fe, etc.) catalyzed coupling of haloarenes 6aa and heterocumulenes.…”

Organic Base-Catalyzed C–S Bond Construction from CO2: A New Route for the Synthesis of Benzothiazolones

“…As a typical sulfur-containing organic compound, benzothiazolone and its derivatives are very important chemical and biological intermediates, and are widely used in the synthesis of agricultural chemicals, dyestuffs, pharmaceuticals, and achiral templates for asymmetric catalysis [1][2][3][4][5]. To date, numerous efforts focused on the development of improved methods for the synthesis of this heterocyclic compounds [6][7][8][9][10].…”

“…However, due to the inherent kinetic inertness and thermodynamic stability of CO 2 , developing highly efficient catalysts is a key step for the cyclocarbonylation of 2-aminothiophenols with CO 2 …”