getting gradle dependencies in intellij IDEA using gradle build

Grade build, even from inside Intellij IDEA does not put the dependencies into the External Libraries folder, so these classes don't show up as suggestions in the editor and when i manually add them as an import there is a compile error.

How can I get IntelliJ to automatically incorporate the dependenciers in my build.gradle file, for instance

compile 'com.google.code.gson:gson:1.7.2