My DS7 had the same issue when he was in kindergarten. He had no friends and was not interested in talking to anyone. All he was interested was in big English words, word puzzles and geography at the time. I can see why he couldn't find anyone to talk about those topic at school. The social worker at the school got involved and asked him to find a boy from the class that he thought he could hang out with. Then she pulled the two boys out of the regular class and had them play together things like lego, drawing and puzzles. They had fun together. They did not end up as best friends but I think that showed my DS he could find friends with common interests if he wants too. He had a great year in 1st grade in terms of making friends at school. It may take some time but if you can find that "one" like Portia said, that would be great start :-)
