can we use documentdb with sharep

As in how do you wish to use it? DocumentDB is a NoSQL document database service designed from the ground up to natively support JSON and JavaScript directly inside the database engineand SharePoint is, well, SharePoint. I'm not understanding what you are trying to do with DocumentDB in SharePoint. You could certainly create something custom with JavaScript that would access DocumentDB, my suggestion would be to do it within the App development paradigm.

Is that what you are asking?

Thanks Greg. I am trying to avoid turning sharepoint into dotnet solution with SQL custom tables.

I can not store things in lists(no transactions, no tool to manage lists)

Hi Amit,

Per my knowledge, DocumentDB is not supported to be used for SharePoint for now.

As Greg said, you may use it for App development or use it as a backup tool:

https://rockwithazure.wordpress.com/2015/03/01/sharepoint-online-backup-in-azure-documentdb-tool-first-step-with-documentdb/

Thanks,

Victoria