Singh Manpreet, Paul Avijit Kumar, Singh Virender
Department of Chemistry, Dr B R Ambedkar National Institute of Technology (NIT) Jalandhar, 144011, Punjab, India.
Department of Chemistry, National Institute of Technology (NIT) Kurukshetra, 136119, Haryana, India.
Org Biomol Chem. 2020 Jun 3. doi: 10.1039/d0ob00888e.
A transition metal-free, convenient, and efficient practical approach has been devised for the synthesis of substituted 2-(2'-aminophenyl)benzothiazoles via a sulfur insertion strategy using isatin derivatives as 2-aminobenzaldehyde surrogates. KI assisted one-pot operation of isatin, arylamines and elemental sulfur resulted in the formation of a C-N and two C-S bonds and cascade cleavage of the isatin ring resulting in the formation of 2-(2'-aminophenyl)benzothiazoles. The significant features of this strategy are the readily available and inexpensive starting materials, broad substrate scope, sustainable reaction conditions and high yield of products. Importantly, the strategy was found to be appropriate for gram scale synthesis (>10 g) of 2-(2'-aminophenyl)benzothiazole derivatives. Moreover, the excellent photophysical properties (ΦF up to 60%) of 2-(2'-aminophenyl)benzothiazole derivatives provide huge scope in materials science.
已设计出一种无过渡金属、简便且高效的实用方法，通过使用异吲哚酮衍生物作为2-氨基苯甲醛替代物的硫插入策略来合成取代的2-(2'-氨基苯基)苯并噻唑。碘化钾辅助异吲哚酮、芳胺和元素硫的一锅法操作，导致形成一个C-N键和两个C-S键，并使异吲哚酮环发生级联裂解，从而形成2-(2'-氨基苯基)苯并噻唑。该策略的显著特点是起始原料容易获得且价格低廉、底物范围广泛、反应条件可持续以及产物收率高。重要的是，该策略被发现适用于2-(2'-氨基苯基)苯并噻唑衍生物的克级规模合成（>10 g）。此外，2-(2'-氨基苯基)苯并噻唑衍生物优异的光物理性质（荧光量子产率高达60%）在材料科学领域提供了广阔的应用前景。
