Synthesis of 3,6-Divinyl-1,2,4,5-Tetrazine, the First Member of the Elusive Vinyltetrazine Family - Pican, Stéphanie; Lapinte, Vincent; Pilard, Jean-François; Pasquinet, Eric; Beller, Lionel; Fontaine, Laurent; Poullain, Didier (Synlett, 2009)