I had the, er, honor of converting an old ANT build to Gradle. It was one of those with the directories filled with jars and was having a hard time figuring out what dependency was still in use, what the versions were, etc. That is when I found a pom.xml file hidden away. It seems that the build process including manually supporting this Maven POM as well and the ANT build to get it to Artifactory.
I looked at the dependency list — not too long but longer than I wanted to copy, paste and manipulate. With any Googling, I quickly wrote my own Python script for it. That worked well for a first swipe. I had to do some tweaking for exclusions, etc, but it wasn’t a complicated script. See my Gist and convert away!