Hi, I have installed the JMS component in the master site and in the slave site (because I have to use Article sharing fot JMS on both), but in the slave site i have an alert:
* Some patches are not installed.
* Please check patches and proceed with patch installation to allow mutlisites working properly.

So, I have to proceed with the installation of Patches in the slave site????

First JMS Multisites should not be installed in a slave site (event when using the Article Sharing for JMS).
The objective of JMS Multisites extension is to add functionalities to convert a "standalone joomla" in a master.
So you can not convert a "slave" in a "master".
This is the reason why it is mentioned that patches are missing and that you can not install them because we have disable the installation of patches in a slave site.

Uninstall JMS Multisites in the slave site.
It is not designed to manage the slave site from a slave site.

The article sharing component requires the JMS Multisites component and is neccesary to install in a slave site because I want to share contents of the master site in the slave that has its owns contents and some contents of the master. Are you shure that the JMS installation is not required for the slave who need to have Article sharing?

YES.
As you are sharing the same Joomla PHP code, the article sharing is able to read directly the JMS Multisites low level API to perform all the necessary access to read the articles coming from the other websites.

You just have to install the "Article Sharing for JMS" in each website that needs to display articles coming from other websites.