Intermolecular C−Cl Activation Reaction of (η 5 -C 5 R 5 )Re(CO) 3 (R = H, Me) with Pentachlorobenzene: X-ray Structure of cis - and trans -(η 5 -C 5 Me 5 )Re(CO) 2 (2,3,4,5-C 6 HCl 4 )Cl and Its Conversion to (η 6 -C 5 Me 4 CH 2 )Re(CO) 2 (2,3,4,5-C 6 HCl 4 )
2000; American Chemical Society; Volume: 19; Issue: 13 Linguagem: Inglês
10.1021/om000032v
ISSN1520-6041
AutoresA. Hugo Klahn, Adriana Toro, Beatriz Oelckers, G.E. Buono-Core, Vı́ctor Manrı́quez, O. Wittke,
Tópico(s)Catalytic Cross-Coupling Reactions
ResumoPhotochemical reaction of (η5-C5R5)Re(CO)3 (R = H, Me) with pentachlorobenzene (λ = 350 nm, hexane solution) yields trans-(η5-C5R5)Re(CO)2(2,3,4,5-C6HCl4)Cl (trans-1, R = Me; 2, R = H) formed by insertion of the fragment (η5-C5R5)Re(CO)2 into the C−Cl bond of C6HCl5. Complex trans-1 converts to cis-(η5-C5Me5)Re(CO)2(2,3,4,5-C6HCl4)Cl (cis-1) in MeCN. The stereochemistry of both isomers has been assigned from examination of ν(CO) IR intensities and is supported by an X-ray structure determination of both complexes. A pure sample of either trans-1 or cis-1 dissolved in organic solvents produces an equilibrium mixture. In nonpolar solvents trans-1 is favored, whereas cis-1 is more stable in polar solvents. A mixture of cis-1 and trans-1 in CH2Cl2 solution reacts on silica gel to produce the new tetramethylfulvene complex (η6-C5Me4CH2)Re(CO)2(2,3,4,5-C6HCl4), 3.
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