I don’t understand why your boss would want to do that seeing that the TOC links to headings on the current page! For each link someone clicks on, it’ll be loading the same page, except it will be at a different position. When the user prints the page, they’ll get all the content, not just the section that popped up.
Maybe the content should be broken up into nested pages instead?
There are other more elegant ways and promotes usability too:
1. Fix the TOC so it is always visible and to the side as the user scrolls or moves between headings.
2. You could also highlight the section of the TOC that the user is currently in.
3. Use smooth scrolling to animate to the headings to give a ‘wow’ effect.
For an example of the 1 and 2, take a look at Bootstrap and start scrolling.
Edit: there is no existing option to open in new windows – don’t hold your breath either as I would not be recommending this approach.