For the future, your first mistake was in allowing this happen because you were new. You totally gave away any authority/influence you have. It is harder to get it back after you give it away.
Next, the first problem is not the subordinate, but your boss. He is the only one who can salvage this at this point. He should never have allowed the person to go around you.
So the first thing you do is go to your boss and have a heart-to-heart. Tell him that in allowing this person to bypass you, he is making it more difficult for you to manage this person. Ask your boss to please send this person back to you anytime he directly contacts your boss, no exceptions. Then ask your boss to help you get better at answering questions by providing you the information he would have given the employee in a separate email. That way you will have the information when the employee goes to you and you will start to build the knowledge that you need to be effective in this organization.
Part of the political dynamic going on here is that he is prossibly upset at not being chosen for your position (or at a friend not being chosen if he didn't apply). You said it was open internally and they did not hire anyone. Talk to your boss about whether this person was interested in the job and if so, why he was not chosen. Ask what prevented them from hiring internally. You can't fix a problem until you know what the problem is. If he wanted and got turned down for the position or if he thought someone else internally should have gotten the postion, he may very well be deliberately trying to make you look bad in which case the moves are different than if he is genuinely doing this to speed of the process from his perspective.
Think how you would feel if you had worked somewhere a long time and someone from outside was brought in with no knowledge of the systems and made your boss. Even if you had not applied for the job, you would likley resent working for someone with less knowledge than you have. That's just how human nature is.
So part of the challenge is that you have to get this guy on your side (and the rest of your team as well), because he is someone respected in the organization and whose opinion of you matters a great deal.
This means you need to talk to him. You need to completely hear him out without being defensive. You need to ask him what he needs from you. You need to find out why he is going around you and how you can fix that. You need to know whether he wants to be promoted and, if so, to what postion. You need to know his background and you need to make sure that he clearly understands that you respect his professional abilities (even if his attitude leaves something to be desired.). You need to find out, in short, what needs to change and how you can help turn this guy's opinion of you around.
You may hear some unpleasant things when you ask. It is cricial to not get defensive and to think after the meeting about whther there is any validity in what he says. You should probably have this conversation with others on your team as well. If they all say the same thing, it is very possible that they perceive the problem to be you. You may need to make some changes in how you manage them. I don't know you and I don't know them, so it is hard to say if this will happen. It is more of a warning that it could and to be mentally and emotionally prepared for it to happen before you start having such conversations.
Remember if he says something you don't like, the worst possible move to make is to get angry. He has the respect of this organization and you have not yet built that same level of respect. In any angry confrontation, the organization is likely to come down on his side.
Now as far as the employee ignoring emails you send him, that has to stop. You need to tell him that when you ask for something, he needs to respond directly to you and that if you ask something, he needs to respond by the date in the email. You have to make your exceptations crystal clear. Now make sure any emails do have a respond by date in them and if he does not respond by that time, you go directly to his desk and ask him why he has not responded. I would do this is in a separate conversation only after trying talking to him about what his concerns areand talking to the boss about rerouting anything the employee sends him and seeing if that doesn't help change your relationship before you take this step.
If after all this, he still won't change, then you need to discuss more serious steps with HR (you should be fully aware of what steps you need to take at this company with a perceived problem employee in any event). Truth is that while many people can be turned around when a relationship gets off on the wrong foot, some cannot.