Whisk together the orange juice, vinegar, marmalade, pepper flakes, ginger, garlic, and olive oil. Pour over chicken and marinate for at least 8 hours, or overnight.
Remove chicken from marinade and pat dry. Sprinkle both sides with kosher salt.
Heat a grill pan or outdoor grill until hot. Brush grill with canola oil. Turn down heat to medium-high. Place chicken pieces on the grill and grill 3 minutes per side, or until cooked through. Let rest for 5 minutes before slicing.