High trans-1,4 (co)polymerization of β-myrcene and isoprene with an iminophosphonamide lanthanum catalyst

β -Iminophosphonamide ligated lanthanum bis(benzyl) complex (NPN Dipp )La(CH 2 Ph-4-Me) 2 (THF) (NPN Dipp = Ph 2 P(NC 6 H 3 i Pr 2 -2,6) 2 ), upon activation of AlEt 3 and [Ph 3 C][B(C 6 F 5 ) 4 ], exhibited high catalytic activity and high trans -1,4 stereoselectivity for the polymerization of bio-sourced β -myrcene (MY). Based on which, a series of novel trans -1,4 regulated elastomers could be generated by random/block copolymerization of MY and isoprene (IP).