Your disk has a GPT partition table, for a Linux system to be able to install a bootloader you need to have a “BIOS boot” partition. It can be a 1 MB partition on the start of the disk, but requires bios_grub flag assigned to it.
bios_grub
More info:
https://wiki.archlinux.org/index.php/partitioning#Choosing_between_GPT_and_MBR