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Reactions of (η5-C5H5)(η5-C5Me5)Zr[Si(SiMe3)3]X (X  Cl, Me) complexes with carbon monoxide and the isocyanide 2,6-Me2C6H3NC. Crystal structure of (η5-C5H5)(η5-C5Me5)Zr[η2-C(N-2,6-Me2C6H3)Si(SiMe3)3]Cl

1988; Elsevier BV; Volume: 358; Issue: 1-3 Linguagem: Inglês

10.1016/0022-328x(88)87078-5

1872-8561

Frederick H. Elsner, T. Don Tilley, Arnold L. Rheingold, Steven J. Geib,

Organometallic Complex Synthesis and Catalysis

The new tris(trimethylsilyl)silylzirconium derivative (η5-C5H5)(η5-C5Me5)Zr[Si-(SiMe3)3]Cl (1) is prepared by reaction of (η5-C5H5)(η5-C5Me5)ZrCl2 with (THF)3LiSi(SiMe3)3. Mixed alkyl/silyl complex (η5-C5H5)(η5-C5Me5)Zr[Si(SiMe3)3]Me (2) is obtained after treatment of 1 with MeMgBr. Reactions of compounds 1 and 2 with carbon monoxide and 2,6-Me2C6H3NC are described. Carbon monoxide inserts cleanly into the ZrSi bond of 1, giving the η2-silaacyl (η5-C5H5)(η5-C5Me5)Zr[η2-COSi(SiMe3)3]Cl (3). The reaction of 2 with CO proceeds via the intermediate (η5-C5H5)(η5-C5Me5)Zr[η2-COSi(SiMe3)3]Me (4) to the enolate hydride (η5-C5H5)(η5-C5Me5)Zr[OC)CH2)Si(SiMe3)3]H (5). A mechanism for this rearrangement is proposed. This chemistry contrasts with that previously observed for (η5-C5H5)2Zr[Si(SiMe3)3]Me, which reacts with CO to cleanly give the stable acyl (η5-C5H5)2Zr[Si(SiMe3)3](η2-COMe). Methyl iodide and compound 5 react to give the iodide (η5-C5H5)(η5-C5Me5)Zr[OC(CH2)Si(SiMe3)3]I (6) and methane. The reaction of 5 with 2 equivalents of HCl provides a new synthetic route to an acylsilane, MeCOSi(SiMe3)3. Reactions of 1 and 2 with the isocyanide 2,6-Me2C6H3NC give the insertion products (η5-C5H5)(η5-C5Me5)Zr[η2-C(N-2,6-Me2C6H3)Si(SiMe3)3]Cl (7) and (η5-C5H5)(η5-C5Me5)Zr[η2-C(N-2,6-Me2C2H3)-Me]Si(SiMe3)3 (8), respectively. Steric crowding in these compounds is evidenced by restricted rotation about the NC(xylyl) bonds. An X-ray crystal structure of 7 has been determined. Crystals of 7 are monoclinic, P21/c, with a 18.276(6) Å, b 9.993(3) Å, c 21.550(5) Å, β 106.25(3)°; V 3779(2) Å3, Z = 4, RF 6.63%, 6.63%, RwF 6.48%.