Synthesis, Structure, Spectroscopy, and Reactivity of a Metallathiabenzene 1
2001; American Chemical Society; Volume: 20; Issue: 10 Linguagem: Inglês
10.1021/om010050s
ISSN1520-6041
AutoresJohn R. Bleeke, P.V. Hinkle, Nigam P. Rath,
Tópico(s)Cyclopropane Reaction Mechanisms
ResumoTreatment of (Cl)Ir(PEt3)3 with lithium 2,3-dimethyl-5-thiapentadienide leads to the production of (4) via C−H bond activation. Oxidation of 4 with silver tetrafluoroborate in tetrahydrofuran generates "iridathiabenzene", (3). The structural and spectroscopic features of 3 are consistent with the presence of an aromatic ring in which the iridium center participates in ring π-bonding. Treatment of 3 with excess PMe3 or with PPN+Cl- leads to the production of (5) or (6), respectively. Each of these products features an iridathiacyclohexa-1,3-diene ring system. The reaction of 6 with 1/2 equiv of silver trifluoromethanesulfonate leads to the production of a novel iridium dimer, (7), in which the two iridium centers are bridged by the two sulfur atoms of the iridathiacyclohexa-1,3-diene rings, as well as a chloride ligand. Treatment of 3 with nitrosobenzene generates a [4 + 2] cycloadduct, (8), containing an iridathiacyclohexa-1,4-diene ring. Compound 3 cleanly displaces p-xylene from (η6-p-xylene)Mo(CO)3 in tetrahydrofuran, generating (9). When 9 is reacted with excess trimethylphosphine, PMe3 adds to the molybdenum center, causing the iridathiabenzene ring to slip from η6 to η4 coordination and forming (10). Finally, treatment of (η5-C5Me5)Ru(NCMe)3+O3SCF3- with 3 leads to clean displacement of the acetonitrile ligands by the iridathiabenzene ring and generation of the Ru sandwich compound (11). Compounds 3, 4, 6a, 7, 9, and 10 have been structurally characterized by X-ray diffraction.
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