A tandem one-pot synthesis of polysubstituted 1,3-thiazines has been developed by reacting with cyanoacetamide and isothiocyanate derivatives to give rise to 2-cyano-3-mercaptoacrylamides, which are trapped in situ by various aldehydes or diversely substituted ketones through intermolecular cyclization, providing polysubstituted 1,3-thiazine derivatives in short reaction times with good to excellent yields. The salient features of this novel protocol are operational simplicity, accessing the desired products from the readily available starting materials and easy of product isolation and may find wide spread applications in medicinal chemistry.
Concise and efficient three-component domino [4＋ 1 ＋ 1] carbocyclization to highly substituted fluoren-9-one derivatives promoted by K2CO3 has been developed under microwave irradiation conditions. The direct bis-cyanation and aryl amination residing in fluoren-9-one framework were achieved in a one-pot operation. The reaction proceeds at fast rates and can be finished within 30 min, which makes workup convenient to give good to excellent chemical yields.
Ying Li Haiwei Xu Liping Fu Qingqing Shi Bo Jiang Shujiang Tu
New cycloaddition has been established for the synthesis of indoline-spiro benzofurodiazepine derivatives. Those reactions were conducted by reacting readily available and inexpensive starting materials, such as ben- zene- 1,2-diamines, tetronic acid and indoline-2,3-diones, in aqueous solution under microwave irradiation. When mono-substituted benzene-l,2-diamines as an amine component was employed, the reaction regioselectively re- sulted in the poly-functionalized indoline-spiro benzofurodiazepine with good yields. The present green synthesis shows attractive characteristics such as the use of water as reaction media, concise one-pot conditions, short reaction periods, easy work-up/purification and reduced waste production without the use of any strong acids or metal promoters.
