Is it possible ? Sql Server as publisher(master) and PostgreSql as slave(subscriber) ? Any type of replication really.
Also, from sql server 2012, this is being depreciated as well.
Heterogeneous replication to non-SQL Server subscribers is deprecated. Oracle Publishing is deprecated. To move data, create solutions using change data capture and SSIS. Caution : This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature.
Below is a blog post that I found that might be useful to you: Replicating from MS SQL Server to PostgreSQL