Use unicodeit for a web latex-to-unicode converter.
If you want to setup a keybinding
If you're on linux install
pip install unicodeit and do something like
#!/bin/sh python -m unicodeit.cli "$(xsel)" | xclip -selection clipboard unicode=$(python -m unicodeit.cli "$(xsel)") echo "$unicode" | xclip -selection clipboard notify-send "copied $unicode"
If you're on mac follow the automator setup described here.
If you're on windows I feel sorry for you, but you can probably setup a keybind with autohotkey.