OS X does not inicialize

When I turn on my Mac, it just processes and finally It shut down instantly without entering the system what it may be? I tried to enter into security mode, but the same happens, I entered the recovery partition and tried to repair the disk, the Repair process fails and asks to backup the information, but without entering the system I can not back up the information, what I do now, how do I save all my information and recover the system? I have no time machine backup,

Has no external ssd drive nor onther macbook with same ssd compatible, is ther onther option to same my information ?