It’s possible to do it, but you won’t like what happens as the wood dries. I did it with partially dried wood for a fence where I thought it wouldn’t matter and it’s cracked even with pre-drilled holes for all the fasteners and warped so much it has to be redone. I did another section with wood dried to around 12-14% and that section is solid and straight. I would never do anything with green wood that needs to remain square and structurally stable.