iTunes only allows one-way transfer, from iTunes to iPhone, not the other way around. You will need some iPhone-to-mac transfer program to help you.
Before you jailbreak or Upgrade Iphone system,you must backup all your iphone files to computer or Mac avoiding lost iphone data,including SMS messages,Contacts,Call lists,games,video,song playlists,photo and so on.
If you want to backup iphone SMS and contact to computer/Mac, you need to use the third software,because iTunes only support transfer Multimedia files,you need use the third software to manage your SMS and contact on computer/Mac.
I have ever use a useful iphone bakcup tool kit,I remember it name Cucusoft iPhone Tool Kits
Cucusoft iPhone Tool Kits can help you backup iphone SMS messages&contacts,games,songs, videos, books, photos and so on to computer.
Next,I share you the free download link:
hotdownloads.com/trialware/download/Download_iPhoneToolKits_reg.exe?item=18286-5&affiliate=406676
More infor:
recovery-iphone.com