I am a Project and Team Leader for a successful team that ensure effieciency in internal services. We are successful and I have risen through the ranks and have a great rapport with my boss. A new team member lets call him Jay keeps bringing his ideas directly to my boss. Jay has great ideas but they are typically rough and not thought out pass the initial stages. My boss is pretty annoyed about this--and needless to say I am as well.

I have tried being diplomatic--open, clear, explaining that I am here to facilitate his work product and increase his opportunities within our company.

This is not lateness, late deadlines, and although his work is unrefined--I have worked with worst that improved over time.

This is office politics which is beyond my talents.

How do you get a junior employee to stop going over your head and talking to present his work to your boss.

First , you get together with your boss to make sure he will back you up.
Then you tell the offending party that he will not go directly to your boss about anything. All if it will come to you, and if you feel it has merit or requires your boss's input. then you will be the one to present it to your boss. Remind Jay there is a chain of command in your office and it will be adhered to.