A Palladium‐Catalyzed Method for the Synthesis of 2‐(α‐Styryl)‐2,3‐dihydroquinazolin‐4‐ones and 3‐(α‐Styryl)‐3,4‐dihydro‐1,2,4‐benzothiadiazine‐1,1‐dioxide: Access to 2‐(α‐Styryl)quinazolin‐4(3H)‐ones and 3‐(α‐Styryl)‐1,2,4‐benzothiadiazine‐1,1‐dioxides.