replacing curly brackets and text in it with node

I have a string

var str="Hello my name is {john/www.john.com} and welcome to my {site/www.site.com}."

i have extracted curly brackets and made an anchor tag out of them like

<a href="www.john.com">john</a>

What i am trying to do is replace curly brackets and content in them with these nodes. Is it possible using regExp? I have studied regExp on MDN but still cant figure out the way.