Heat oil in large heavy skillet. Sprinkle chicken with salt and pepper. Add to skillet and saute until browned on all sides about 10 min.
Add 2 Tbsp reserved marinade, broth, lemon juice, peel, and red pepper. Reduce heat to low, cover, simmer until chicken is almost cooked through, about 10 min.
Uncover, stir in artichokes & 2 Tbsp oregano. Simmer until liquid is slightly reduced and chicken is cooked through, about 5 min.
Stir in 1 Tbsp oregano and season with salt and pepper.