Shoot web when he has stopped attacking for a moment. This then triggers one of those scenes and you can grab his tail. Swing him round and launch him into each of the 4 generators then ust get in there and pound him.

It's the same on all formats (bar Wii).  You have to keep playing it over and over again to learn the moves and only hit when you have a free moment (when he's not attacking). 

All the boss battles seem to be this way, it's a pain.

Oh, and check the walkthroughs section soon, I'm sure someone will post (or maybe has already) a complete walkthrough for the game.