Superchargers are a waste but I believe you can however turbo 2 strokes without a reed valve since any air that get blown to the exhaust will just end up spooling the turbo even more, and well the faster the air moves through the cylinder the more it will compress when it's sent back in. (see picture)

Bottom line though is that it's just not practical. You could make a cheap little turbo and half arse it but in order to make something worthwhile the machine work and labor involved would cost about a grand...

Look at full size super charges and turbos.... they cost 5000. when you look at them they are very intricate and take perfect tolerances in order to kept boost. It's just not practical in our little rc engines.