I know you can, but I haven't seen it done yet. The only thing you're required to use junk for is the teleporter to get into the institute, which most factions will supply you the majority of junk for, with only a few pieces missing. You can buy those at Carla's or any other junk vendor assuming you've saved enough caps from quest rewards and the like. From there you don't need to scavenge for anything else, long as you've purchased a good enough melee weapon and armour. Or have the skills to go it naked if you really don't wanna touch anything.

(Assuming you're talking about Fallout 4. I don't believe you need to scavenge for anything in 3 or New Vegas though, with NV probably being the easiest since you can do the NCR path without any items in your inventory, they're the only ones who don't care about the platinum chip. I wouldn't know about 2 or 1.)