I have a website with multiple domains. I manage a section that is part of a larger site. The section used to be a separate site and so the old domain has a 301 redirect to the section on the new site. Unfortunately the old domain is very established with a lot of searches. Therefore I want to feature the old domain name in my adword copy. The issue is that Google wouldn't accept the domain due to the 301 redirect. If I setup an alias this will impact SEO as I'll have duplicate content. Does anyone have any suggestions?