There are some tools for linkedin automation, however it's kinda difficult to get them, especially free of charge. I guess it's almost impossible to find them for free. I believe that everything depends on what you want to get from this automation. If you want to automate the search for companies, pursuiting the goal to attract new prospects, then I know exactly that there are some sources, but you will have to pay for them. Otherwise, you can determine another direction of your work and find some free tools. It's kinda difficult and you have to dedicate some time to it, but it's possible I'm sure.