Palladium-mediated stereospecific synthesis of 3-enynyl substituted thioflavones/flavones via sequential Heck–Sonogashira strategy

ORGN 91

Manojit Pal, Karuppasamy Parasuraman, Venkataraman Subramanian, Rambabu Dakarapu, and Koteswar R. Yeleswarapu. Chemistry-Discovery Research, Dr. Reddy’s Laboratories Ltd, Bollaram Road, Miyapur, Hyderabad, 500049, India
Sequential palladium catalysis is utilized for the stereo-controlled synthesis of enynes in a simple synthetic operation. A variety of terminal alkynes were reacted with 3-iodo(thio)flavone in the presence of palladium catalyst and a copper salt involving a mild and convenient method which resulted in 3-enynyl and/or alkynyl derivatives of potential biological interest. The mechanism and scope of the reaction will be discussed.