I do not know of any perennial shrub that repels insects but you could plant a scented geranium called a citronella geranium or "mosquito plant" that has a strong lemon scent and repels mosquitoes. Other strongly scented plants such as lavender, garlic, lemon balm and catnip also have fragrance that keep some insects at bay.  For your location with just half a day of morning sun I vote for the catnip plants - a member of the mint family.  There are several types of catnip or Nepeta so ask at your local garden center if they can order you some of the taller types. Some varieties are invasive so cut back all the faded flowers after this member of the mint family blooms. Keep growing, Marianne Binetti