[EDIT for more depth] If thinking is emergent, we'll eventually make a machine that thinks. Unless you think we have imbued it with a soul, there you will have an example of a materialistic basis for thinking. As a side effect of showing a materialistic basis for thinking it will probably also overturn a lot of psychology, and demonstrate that how we think we think, and even what we think we think is wrong.
I am an anti-materialist and I think machines can almost certainly be made to exhibit general intelligence, and possibly even (I am not sure about this) to achieve "really real" thinking a la consciousness and self awareness. I don't see either of those eventualities to be in conflict with my anti-materialism.