Is there a possibility, to download a dependency and all it´s related dependencies from MavenCentral?
Yes, if you just want to have the artifact, with its transitive artifacts, but without the metadata, you can use a Copy task.
Task getDeps (type : Copy) {
from configurations.compile // copies all compile dependencies
into myDestinationDir
}
If you wany something more complex, then you need to look at the Ivypot plugin.