This is not legal -- just like NFHS.
Rule 9-11-5 addresses the throw-in exception, which covers a player catching the ball with both feet off of the ground and then landing with one or both feet in the backcourt.
However, there is no exception for passing the ball once it is received in the frontcourt.
A.R. 20 Addresses this, even thought it doesn't specify the case of a player catching the throw-in while not touching the floor, certainly that scenario qualifies as "receiving" the pass, so it's pretty clear that this
is a violation.
A.R. 20. A1 receives a pass in Team As front court and throws the ball to his or her back court where the ball (a) is touched by a teammate...
RULING: Violation when touched in (a)...