The Dutch winger has completed his medical with Derby, ahead of joining on a four-year deal.
'Sky Sports' reported that Leeds has matched the £2.75million bid, both of which were accepted by Brentford.
Jozefzoon, who scored seven goals in 43 appearances last season, joined Brentford from PSV Eindhoven in January 2017.
The 27-year-old only had a year left on his contract at Griffin Park.
Brentford have already got his replacement sorted, having signed Said Benrahma from Nice on a four-year contract.