Use BeLive with YouTube Live
Be.Live, or BeLive TV, recently released YouTube Live Beta. You can find the option inside BeLive Studio2. Click the stream settings in the top left, and you will see the option to select YouTube as your destination.
The integration is still in Beta and has a fairly limited set of features. If you are looking for a YouTube live tool that includes more features like scheduling, Super Chat integration, simulcasting, and moderation options, try StreamYard.