iPhone doesn't sync over WiFi
Here are the standard steps to set it up:


Make certain that your computer and iPhone, iPad, or iPod touch are connected to the same Wi-Fi signal.
Connect your iPhone, iPad, or iPod touch to a Mac or PC via USB. Launch iTunes if it doesn’t do so automatically.
Highlight your iDevice in the sidebar. (or choose at top right if iTunes11)
Click "Summary" in the menu bar. Scroll down to the "Options" section.
Check the "Sync with this (iOS device) over Wi-Fi" box. Click "Apply."
Detach your iPhone, iPad, or iPod touch.
Initiate an iTunes Wi-Fi Sync by tapping Settings > General > iTunes Wi-Fi Sync > Sync Now on your iPhone, iPad, or iPod touch. Or, plug it into an outlet


Does it fail at a particular point?  

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