Suggestions on syncing meta data from document library and list in SharePoint

[sobenson]

I am working with my HR department and the have a document library of Job Requisitions.  They are adding meta data (choice columns, Single line of text, Multi line of text)to the files in the library.  This library is for Team leaders to find reqs to use to hire new employees.   The HR Team wants to add add private meta data that the leaders should not see.  My thought was to add a second list with the meta data synced and then additional columns.

I would like to sync the lists both ways, so when something is added to doc library, entry is made on list.  When list item is updated or changed, meta data on doc library is updated.

Does anyone have a suggestion, or another option?