>>33116032So 2% base, and assuming you're good enough to reliably do a curve ball and land a Great.
2 x 1.7 (curve ball) x 1.5 (Great!) = 5.1%
A Golden Razz increases catch chance, but I don't know how much. According to a raid capture chart on pokemongohub it roughly quadruples the base catch rate (goes from ~8% to ~32%).
Therefore, a Golden Razz fed Pokemon hit by a Great curved ball should be.... 5.1% x 4 = ~20.4% chance per shot. It might be less due to being Legendary, so I'll guess ~10%-20% chance.