Sorry if old–article is from 2013:
http://www.foxnews.com/politics/2013/11/24/report-claims-secret-us-iran-talks-laid-groundwork-for-nuclear-deal.html
Here is a link to Kerry's visit to Oman 5/22-5/23. Not sure if relevant, but there are about 40 images tied to the trip, including one with this group called the "London Eleven":
https://2009-2017.state.gov/secretary/travel/2013/t7/index.htm