Automatic reboot using cron

1. Your line is commented out so never performed
   -> delete the # at the start

2. It should be * * * * * for every minute

3. (Thanks to @Rinzwind) reboot does not work It has to be
   systemctl reboot -i

So in the end in your file there should be the line

* * * * * systemctl reboot -i

-i here stands for ignore-inhibitors. Some programs put this inhibitors lock to prevent dataloss so you wouldn't reboot but get a note in the command line.

This should do the trick

Note: Not letting unmentioned here that this doesn't seem a smart idea to me ... Why do you want that? And make sure you are able to revert this before your system reboots again when you don't want this anymore ;)