This thesis is basically deals with Gold-catalyzed organic transformations appropriately functionalized organic molecules. The thesis divides in to two chapters better understanding. The first chapter describes with Gold-catalyzed oxidative cyclization of 1,5-enynes via 5-endo-dig cyclization involving with 8-methylquinoline N-oxide as oxidant. The utility of this reaction is manifested by the synthesis of a number of indanone derivatives. The second chapter discusses a gold-catalyzed isomerization of unactivated allenes into 1,3-dienes with nitrosobenzene as an additive. This reaction proceeded almost exclusively at ambient temperature for highly substituted allenes.