Publishing a single-author paper This is the situation. I am a postdoc at a German university. Unfortunately, my boss is not interested in publishing the research results. He prefers to publish just when it is strictly necessary for project reports and publishes old and unimportant results in most cases. 

Obviously, it is a problem for my academic career, and I want to leave this division but for personal reasons can't do it in the nearest future. Just to mention, I do not work on industrial projects, and I want to publish the results of the projects I work on. It is also worth noting that the results in our area get "old" quite fast, i.e., in a year the community won't be interested in the results as much as it could be now.

The boss also believes that everything that is developed by people working in the division he is the head of is the property of the division = his own ideas (even though I have come up with all of my paper ideas and have executed the research and papers alone) -- and he requires that everything that comes out from the division to the public should be personally checked and approved by him.

Other colleagues seem to be OK with the situation, but I would like to pursue an academic career and get published. 

My question is: if in my free time I study some things on my own that are not included in any project I work on, can I publish the results being a single author? Or, e.g., can I publish a review on the topic on my own? I don't have problems with mentioning the university as my affiliation.
Was someone here in this situation? If so, what have you done about it?
My best guess is that you are well and truly stuck. There may even be contractual considerations that prevent your desired action. Some places (though mostly in industry) claim that anything you produce, even on your "own time" belongs to the institution. You can look to see what binds you legally. 

I also don't know your field and won't judge whether a paper without your supervisor would be looked at a strange or normal - especially if he objects. That expectation varies widely by field. 

But my advice would be to do what ever you can to find a different, and better, situation. Run, don't walk, to the nearest exit. If this means bowing and scraping to the chief to get a good letter of recommendation, then go along for now. 

I don't know how hard it will be to move with few/no publications. But it is usually pretty hard to go without good letters. If you can use him to get a better position you will have a chance for a career.