L.C.
At four, they are out of the stage where they don't have their words and are entering the stage where they are starting to flex their muscles and exercise their will. For me, this has kind of been a tricky stage, because I want them to start making choices, but I don't want them to think that their entire world is up for negotiation. With my kids, a lot of the times these things would happen because they are wanting more control of things. They are "big" boys and girls and are wanting to assert that. At the same time, I don't tollerate disrespect. I say all of that to say that I think it is a combination of consistent discipline and setting up the right environment for him to feel more independent.
This is a good age to start making a standard set of house rules and expectations that are posted on the wall. There should be a SET corresponding consequence for misbehavior and rewards for obedience to the rules. Go over them with him and once they are in place be really consistent. One warning, because at this age he is still really impulsive, and then a consequence. The only one I would make an exception for is the sticking the tongue out. He knows he is being disrespectful, so it's right to time out. Sometimes when I see someone post "we've tried everything" my first thought is that person hasn't tried anything long enough to make the point. If you go from consequence to consequence then you come across as unsure and inconsistent then it all becomes a game of "what will they do if".
The other thing is to start to give him responsibilities and choices. Have "chores" for him, or things he does to help mommy. Things like giving him a baby wipe and letting him "dust" the furniture or wipe down his towels, or folding the wash rags and hand towels. Sorting socks is helpful, and can be fun and educational. Give him choices when you can, for instance, picking between two shirts, two cups, to pairs of underwear, picking between two things for lunch or snack. This will give him some freedom and make him feel more independent. It will also give him practice making choices, both good and bad, and seeing the corresponding consequences.
Hope this helps,
L.