Can we sync existing contacts as net new leads in salesforce after a form fill?

Hi there!

We have a bunch of existing contacts in both salesforce and marketo. We were wondering if there was a way to send these existing people to salesforce as "new leads" whenever they fill out a form. They are syncing over correctly as contacts, but we would love for them to be duplicated and sent over new leads that can easily be picked up and worked by our sales team. Has anyone done anything like this before?

Thanks!