I had the same problem for some times. i tried multiple things like shutting it down and connecting it directly, shutting it down and back up then connecting. But your problem could be also connected directly to Itune. unless there is data that you do not want to lose on it, i would try to reinstal Itune. There is also the Driver that your Iphone use to connect to the computer that could be wrong. As usually, when you connect your iphone, a small driver installation should had started and also ask you if you want to open files or something else. Also, for the best awnser, i would recommend to talk directly with an Apple employee, from their customer services which will point you in the right direction.