Here is the list of people that needs to be sanctioned first. https://nitter.1d4.us/i/status/1496804727199305728
All their direct family became radiactive and assets are removed or thoroughly inspected outside Russia. For example: https://www.forumdaily.com/en/nasledniki-bogatejshix-rossijskix-biznesmenov-zhivushhie-v-ssha/