In the US the first CD games were Fighting Street and Monster Lair. Not sure when the CD unit launched (not sure of the exact date the Turbo launched either or if there even was a real "launch date") but I do know the CD unit was available in the US by October 1989 because I remember seeing one for sale when I bought my TurboGrafx-16. Fighting Street was also there for sale, but not Monster Lair. I have promotional material for the launch of the Turbo with HuCard and CD lineups though, and both Fighting Street and Monster Lair are listed, but Fighting Street had no date (so I assume it was a launch game) while Monster Lair had something like December 1989 listed (I'd have to dig up the old brochure to make sure).
More titles followed in the spring of 1990 (Valis II, Final Zone II, and Last Alert). I remember Ys Book I & II came out in May or early summer 1990.