1½ teaspoons adobo sauce from canned chipotle chiles
Kosher salt and freshly ground black pepper
Combine apricots, ketchup, lemon juice, garlic, and adobo sauce in a small saucepan. Season lightly with salt and pepper and bring to a boil over high heat. Reduce heat to low and cook for another 10 minutes. Remove pan from heat and let cool.
Pour apricot mixture into a blender and purée until smooth. Season to taste with salt and pepper.
Place half the sauce in a medium bowl, add the chicken and coat with sauce. Let marinate at room temperature for 20 minutes. Cover and refrigerate remaining sauce.
Prepare a grill to medium-high heat. Brush grill rack with oil. Grill chicken until browned and almost cooked through, 4-5 minutes per side. Brush on all sides with reserved sauce; grill until glazed and cooked through, 1-2 minutes per side. Serve with remaining sauce.