B. Gautheron

Chlorures de mono- et dialkyl-zirconocene et-hafnocene

Condensation of cyclopentadienyl anions obtained from fulvenes and tetra- chloride metal to prepare (η5-RC5H4)2MCl2, R = alkyl; M = Zr or Hf is described. The prochiral complexes (η5-RC5H4) (η5-C5H5)MCl2 are prepared in a similar way from MCl4 (M = Zr), but the best method uses (η5-C5H5)ZrCl3 or (η5-C5H5)HfCl3, 2THF. Preparation of this adduct is described.

Synthèse de ferrocènes hétérodisubstitués à ancrage soufre ou sélénium via un précurseur original Fe(C5H4ELi)2,2THF (E S, Se). Nouvelle préparation des ferrocènes 1,1′-dithiol et -disélénol

Abstract The reaction of Fe(C 5 H 4 Li) 2 , TMEDA (1 mol) with E (S or Se) (2 mol) in a THF/toluene mixture leads directly to the new reagent, Fe(C 5 H 4 ELi) 2 , 2THF. This complex reacts cleanly with various electrophiles (alkyl halides, acyl chlorides and anhydrides) to give new families of open chains or cyclic heterodichalcogenated ferrocenes. The method describes here is more efficient and convenient than that previously employed.

Synthese et reactivite de nouveaux dihydrurozirconocenes et -hafnocenes substitues achiraux et chiraux

Abstract Hydrogenolysis of (M(CH3)2) (M = Zr, Hf) bonds gives new racemic and optically active substituted zirconocene and hafnocene dihydrides A: (RCp)2MH2 (M = Zr, Hf; R = Me, Me2CH, Me3C, PhCH2) and B: (R*Cp)2MH2 (M = Zr, Hf; R* = MeCHEtCH2, PhCHEtCH2), R*CpCpHfH2 R* = PhCHCH3). Substitution of hydridic hydrogens by halogens, mobile hydrogen compounds, addition with unsaturated derivatives are studied. The A and B type complexes are good catalysts in hydrogenation of alkenes; the B type complexes give only poor asymmetric induction in catalytic reduction of prochiral alkenes.

Synthesis, Structure of Nitrogen-Containing Phosphinogold(I) Ferrocenes. In vitro Activity against Bladder and Colon Carcinoma Cell Lines.

The gold salt [(tht)AuCl] was reacted with [1-N,N-dimethylaminométhyl-2-diphenylphosphino]ferrocene (1) forming the bimetallic derivative 4. The reaction of methyl iodide and tetramethylammonium bromide on the chloride 4 produced the ammonium salt 5 and the bromide 6 respectively. New aminophosphines 2 and 3, which represent two of the rare phosphorylated metallocenes containing P(III)-N bond have also been coordinated to gold(I) to form 7 and 8. The presence of the ethoxy group in 7 provides evidence for the lability of one nitrogen-phosphorus bond. The X-ray structure of compounds 4 and 7 have been established. Both crystallize in space group P21/c, monoclinic, with a = 11.095(2) Å, b = 12.030(3) Å, c = 17.763(4) Å, β= 94.02(2)∘, Z = 4 for 4 and a = 14.863(3) Å, b = 8.036(5)Å, c = 18.062(5)Å, β =101.64(1)°, Z = 4 for 7. 197Au Mössbauer data are in good agreement with those for other linear P-Au-Cl containing complexes. The compounds were evaluated for in vitro anti-tumour activity against two human tumours. Differential cytotoxicity was observed with activity comparable to cisplatin, with the exception of one compound which was significantly more cytotoxic.

Structure cristalline et proprietes du dichlorure de bis(pentahapto-benzylcyclopentadienyl)zirconium triboluminescent

Abstract The product ( n 5 -C 5 H 4 CH 2 C 6 H 5 ) 2 ZrCl 2 is orthorhombic: a 12.05(1), b 24.12(2), c 6.99(1) A; space group Aba 2, Z 4. Final R 0.077. The Zr atom is tetrahedrally coordinated by two ZrCl σ bonds and two ZrCp π bonds. The crystal is tri-boluminescent and highly piezoelectric.

Synthesis and reactions of substituted zirconocene and hafnocene dimethyls and the corresponding dihydrides

Abstract Hydrogenolysis of M(CH3)2(M = Zr, Hf) bonds gives novel substituted zirconocene and hafnocene dihydrides. The use of the optically active complex [η5-C6H5C★H(CH3)C5H4] (η5-C5H5)Zr(CH3)2 as a catalyst in homogeneous hydrogenation of prochiral alkenes is reported.

Ferrocene-based phosphonite–phosphine ligands, Pd and Rh complexes

Abstract A variety of ferrocene-based 1-phosphonite-1′-phosphine ligands were prepared via 1-dichlorophosphino-1′-diphenylphosphinoferrocene from anionic ring opening of 1-phenyl-1-phospha-[1]ferrocenophane. The corresponding palladium and rhodium complexes have also been prepared and tested, respectively, in Heck and hydroformylation reactions.

Pseudoasymetrie dans la serie du benchrotrene I. Synthese des trois glycols ortho-substitues (OC)3CrC6H4(CHOHCH3)2

Abstract The three stereoisomeric glycols (CHOHCH 3 ) 2 C 6 H 4 Cr(CO) 3 have been prepared via 1,2-diformyl- and 1,2-diacetyl-benchrotrenes. The racemic (pseudosymmetric) form and the two meso (pseudoasymmetric) forms of the glycols have been identified by chemical derivatization and analysis of the spectroscopic data. The photochemical decomplexation of these glycols is a specific route for the preparation of the two corresponding benzenic glycols. The stereoselectivity which has been observed in some reactions is discussed.

Composes chiraux du zirconium et du hafnium

Abstract The first chiral dicyclopentadienyl compounds of zirconium (IV) and hafnium(IV) of the form (η 5 -C 5 H 5 ) (η 5 -RC 5 H 4 )MClX (X = alkoxy, aryloxy or benzyl group) have been prepared and studied. The presence of an asymmetric metal atom is shown by NMR of these complexes containing suitable ligands.

FERROCENIC POLYPHOSPHINES AND POLYTHIOETHERS : SYNTHESIS, REACTIVITY AND STRUCTURE

Abstract The new ferrocenic polyphosphines [C 5 Me 3 -1,2-(PPh 2 ) 2 ](C 5 H 5 )Fe 2 , [C 5 Me 3 -1,2-(PPh 2 ) 2 ] 2 Fe 3 , [C 5 Me 3 -1,2-(PPh 2 ) 2 ][C 5 Me 4 (PPh 2 )]Fe 4 and polythioethers [C 5 Me 3 -1,2-(SCH 2 CH 2 CH 3 )2] 2 Fe 6 and [C 5 Me 3 -1,2-(SCH 2 CH 2 CH 3 ) 2 ](C 5 H 5 )Fe 7 have been prepared. The X-ray crystal structures of 3 and 6 have been determined. Some aspects of the reactivity of compounds 2 , 3 and 4 are reported (P(III)→P(V) transformation, chelating properties) as well as the X-ray structure of [C 5 Me 3 -1,2-(PPh 2 ) 2 W(CO) 4 ](C 5 H 5 )Fe 15 .