If you don't have ReSharper installed and still want to use the shortcut Shift
+Alt
+L
to move focus to the current file in Solution Explorer in Visual Studio 2013 then please follow these steps:
In the Show commands containing box type "solutionexplorer" and then in the list below look for the SyncWithActiveDocument command:
Click in textbox under "Press short keys" label and press: Shift
+Alt
+L
and click the Assign button and you are done:
To verify open any file in Visual Studio and press the shortcut keys Shift
+Alt
+L
and you'll see the file in the solution explorer. Enjoy!