Recently, I was asked to synchronize users information with the Active Directory because the company moved to a new location. I was surprised the only tool I could find was for Dynamics 2011. We are running Dynamics 2016 on-premise. So, I created my own using Fiddler and the Web API Service. In summary, it’s using the same service as when you enter the domain name of a new user. I integrated the powershell script inside an SQL Job so it could run every week.
The full detail of the script is here: https://github.com/NickPl/XrmSyncUserAD