C-H bond activation induced by thorium metallacyclopropene complexes: a combined experimental and computational study.

ABSTRACT: Inter- and intramolecular C-H bond activations by thorium metallacyclopropene complexes were comprehensively studied. The reduction of [?5-1,2,4-(Me3C)3C5H2]2ThCl2 (1) with potassium graphite (KC8) in the presence of internal alkynes (PhC 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 CR) yields the corresponding thorium metallacyclopropenes [?5-1,2,4-(Me3C)3C5H2]2Th(?2-C2Ph(R)) (R = Ph (2), Me (3), iPr (4), C6H11 (5)). Complexes 3-5 derived from phenyl(alkyl)acetylenes are very reactive resulting in an intramolecular C-H bond activation of the 1,2,4-(Me3C)3C5H2 ligand. In contrast, no intramolecular C-H bond activation is observed for the diphenylacetylene derived complex 2, but it does activate ?-C-H bonds in pyridine or carbonyl derivatives upon coordination. Density functional theory (DFT) studies complement the experimental studies and provide additional insights into the observed reactivity.

SUBMITTER: Fang B 

PROVIDER: S-EPMC5664364 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature