To transfer contacts and SMS messages to Mac computer,all you need is a iPhone backup tool.Actually, iTunes does not supports backup iPhone contacts and SMS,if you wan to transfer iPhone to computer,you must to use 3rd iPhone backup software.
The iPhone to computer transfer no only can help you backup Contacts, SMS messages to computer,but also supports backup other files,such as music, video, photo and more.If you use Windows computer or Mac,you can free download win/Mac version to backup your iPhone files to iTunes or Computer
How to transfer iPhone contacts to Mac for backup
How to backup iPhone SMS to computer
Tips to transfer iPhone music and video to computer
Use guide to backup iPhone/iPad/iPod to Mac computer