This method will not work for all PDFs - success rate will be better for recently published PDF files where the DOI is embedded in the document.
It will always import the PDF - one option is to then manually enter the required data in the EN library fields or copy and paste the information which will be found in the PDF preview window at the bottom of your EN library.
This feature allows you to import individual pdf files or folders of pdf files into your EndNote library. However the pdf must be in the correct format for EN to do this as it uses embedded DOI information.
N.B. This method will not always be successful - you may only import the pdf without any bibliographic information - the entry will look like this:
<Name of file.pdf>
When this happens you can delete this reference and search for it in a database to import it into your EN library or you can manually fill in the necessary information in the reference fields - you can also copy and paste into the EN fields the information from the pdf which will be attached.
You can set up a folder to automatically import PDFs whenever EndNote is opened.
You simply put PDFs that you want included in your EndNote library into the folder and next time EndNote is opened the PDF is imported and EndNote tries to create a record for the article.
Here is a short video PDF Auto Import Folder to show you how to accomplish this.