as a fgeneral rule, asphalt shingles require a minimum 3/12 or 4/12 pitch.

i would consider shingles fior it in the followin circumatances :

You live in the south where ther is no snow or ice on roofs - ever

You tear off the old and make the sheathing allllll smooth

You dry in with ice and water shield

You reduce the exposure to 4" instead of the tyupiucaaaal 5" or more.

Excellence is its own reward!