This thesis composed of two major parts. The first part mainly contains the carbonylation of aryl halides towards heteroaromatic ring synthesis catalysed by homogeneous palladium systems. The second part includes the investigation of carbonlytive C-H functionalization for the preparation of heterocycle also. The resulted heterocycles such as quinazolinone, isoquinolin-1(2H)-one, phthalimides,isoindoloquinazoliones, 2-quinazolines and N-(2-pyridyl)indoles constitute an important class of life science molecules which are frequently encountered in the medicinal and biological chemistry.