Is it necessary to take leave from work to perform Friday Prayer in a non-Muslim country where there is no nearby mosque, or is it permissible to pray it at the workplace?

If there is no mosque in your area where Friday prayers are held, then Friday prayer is not obligatory upon you; instead, you pray Dhuhr. You are not required to take leave to go to a place where Friday prayers are held if the distance exceeds a farsakh (a little over 5 kilometers). However, if the distance is a farsakh or less, you are obligated to go there. For the people of a metropolis (city), Friday prayer is obligatory whether they are near or far.