In a blender, combine all ingredients aside from chicken; cover and process until smooth. Pour 1/2 cup into a small bowl for basting; cover and refrigerate. Pour remaining marinade into a bowl or shallow dish. Add chicken and turn to coat; cover and refrigerate for at least 30 min and up to 6 hours
Drain chicken, discarding marinade. On a greased grill rack, grill chicken, covered, over medium heat (or broil 4 in. from the heat) until a thermometer reads 165F, 4-6 minutes on each side, basting frequently with the reserved marinade