Metallacyclohexadiene and metallabenzene chemistry, part 17. Synthesis, structure, spectroscopy, and reactivity of a metallathiabenzene

被引:58
作者
Bleeke, JR
Hinkle, PV
Rath, NP
机构
[1] Washington Univ, Dept Chem, St Louis, MO 63130 USA
[2] Univ Missouri, Dept Chem, St Louis, MO 63121 USA
关键词
D O I
10.1021/om010050s
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Treatment of (Cl)Ir(PEt3)(3) with lithium 2,3-dimethyl-5-thiapentadienide leads to the production of mer-CH=C(Me)C(Me)=CHSIr(PEt3)(3)(H) (4C) via C-H bond activation. Oxidation of 4 with silver tetrafluoroborate in tetrahydrofuran generates "iridathiabenzene", [CH=C(Me)C(Me)=CHS=Ir(PEt3)(3)]+BF4- (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 pi -bonding. Treatment of 3 with excess PMe3 or with PPN+Cl- leads to the production of CH=C(Me)C(Me)=CHSIr(PMe3)(4)+BF4- (5) Or mer-CH=C(Me)C(Me)=CHSIr(PEt3)(3)(Cl) (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, [(CH=C(Me)C(Me)=CHSIr(PEt3)(2))(2)(mu -Cl)]+O3SCF3- (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, [CH=C(Me)C(Me)CH=SIrON(Ph)] (PEt3)(3)+BF4- (8), containing an iridathiacyclohexa-1,4-diene ring. Compound 3 cleanly displaces p-xylene from (eta (6)-p-xylene)Mo(CO)(3) in tetrahydrofuran, generating [eta (6)-CH=C(Me)C(Me)=CHS=Ir(PEt3)(3)] Mo(CO)(3)+BF4- (9). When 9 is reacted with excess trimethylphosphine, PMe3 adds to the molybdenum center, causing the iridathiabenzene ring to slip from eta (6) to eta (4) coordination and forming [eta (4)-CH=C(Me)C(Me)=CHS=Ir(PEt3)(2)(CO)]Mo(PMe3)(2)(CO)(2)+BF4- (10). Finally, treatment of (eta (5)-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 [eta (6)-CH=C(Me)C(Me)=CHS=Ir(PEt3)(3)] Ru(eta (C5Me5)-C-5)2+BF4-O3SCF3- (11) Compounds 3, 4, 6a, 7, 9, and 10 have been structurally characterized by X-ray diffraction.
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页码:1939 / 1951
页数:13
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