Reactivity of (C5Me5)2Sm and related species with alkenes: synthesis and structural characterization of a series of organosamarium allyl complexes

The reactivity of (C 5 Me 5 ) 2 Sm (1) with alkenes has been examined and compared with that of (C 5 Me 5 ) 2 Sm(THF) 2 (2) and [(C 5 Me 5 ) 2 Sm(μ-H)] 2 (3). 1 reacted rapidly with a variety of alkenes in hexane or toluene to form allyl complexes and alkane byproducts. Reactions with propene, butene, and allylbenzene formed (C 5 E 5 ) 2 Sm(η 3 -CH 2 CHCH 2 ) (4), (C 5 Me 5 ) 2 Sm(η 3 -CH 2 CHCHMe) (5), and (C 5 Me 5 ) 2 Sm(η 3 -CH 2 CHCHPh) (6), respectively, in 85-95% yield. Complexes 4-6 were also prepared in similar yield from 3 and the appropriate alkene in hexane. Reactions of 3 with these alkenes in toluene formed (C 5 5Me 5 ) 2 Sm(CH 2 C 6 H 5 ) exclusively. 1 reacted with 1,3-butadiene and 1,5-hexadiene to form the bis-allyl complexes [(C 5 Me 5 ) 2 Sm(μ-η 3 -CH 2 CHCHCH 2− )] 2 (7) and [(C 5 Me 5 ) 2 Sm(μ-η 3 -CH 2 CHCH−)] 2 (8). In contrast, 3 reacted with butadiene to form 5. 2 reacts like 1 with allylbenzene and 1,3-butadiene to form 6 and 7