McDonagh, Tatar, Nash, Hartman, Stastny and Brassard were dealt for 1sts in packages at last year's deadline.
Kane and Duchene were traded for protected picks that turned into 2019 1sts. (if the Sharks make the playoffs)
I don't think we'll get 8 1sts dealt this deadline, but 2-3 is possible.
In 2017, Hanzal and Eaves were dealt (latter for a conditional pick) for 1st
2016 was Ladd, Sekera
2015 was Yandle,Perron, Franson, Kane (bigger trade), Vermette
2014 was Martin St Louis
2013 was Iginla, Pomminville, Bouwmeester, Jagr