M. Gruselle

Synthesis and receptor binding of polynuclear organometallic estradiol derivatives.

Twelve novel organometallic derivatives of estradiol were synthesized with the aim of utilizing organometallic cold bioprobes as radioisotopic labels substitutes for steroid hormone receptor assays. For this purpose, we envisaged the attachment of several stable cobalt, molybdenum, osmium carbonyl clusters (tetra- and pentanuclear species) at estradiol 17 alpha-, 16 alpha-, 2- or 4-positions. The binding affinity of these new complexes for uterine estradiol receptor has been measured by the competitive binding method. The results show that the 17 alpha-position can tolerate substitution by bulky organometallic groups (especially in the case of cobalt and molybdenum carbonyl clusters). Estradiol derivatives which are functionalized at C-4 and C-16 alpha bind estradiol receptor with reasonable affinity and the RBA values are the same for the complexed and uncomplexed hormones. The 2- position is more sensitive to organometallic substitution and the complexation at the 2- alkyne results in a dramatic decrease of the RBA values. These results show that the attachment of polynuclear moieties in estradiol 17 alpha-, 4- and 16 alpha-, positions gives rise to compounds which are of potential utility in a new non-radioisotopic receptor assay since the metal-carbonyl markers are readily detected by high-sensitivity Fourier-transform infra-red spectroscopy.

Selectivity in the propargylation of polyfunctional amines by (propargylium)-Co2(CO)6+ and -(C5H5)2Mo2(CO)4+

Abstract [(HCCCH 2 )Co 2 (CO) 6 ]BF 4 ( 1 ) [(HCCCH 2 )Mo 2 (C 5 H 5 ) 2 (CO) 4 ]BF 4 ( 2 ) react with primary and secondary amines in CH 2 Cl 2 solution. In the case of primary amines, the products of mono and dialkylation are obtained. The more stable (less reactive) molybdenum complexes can be employed to alkylate amines in a protic, two-phase medium. The results are interpreted mechanistically and shown to dependent on the thermodynamic stability of the metal-stabilized carbocation.

Stabilisation of carbenium ions species by two different adjacent organometallic moieties: synthesis, NMR study and synthetic application

Abstract A series of carbenium ions, stabilized by two different organometallic moieties in the α,α′ position e.g.: alkynyl-Co2(CO)6 and ferrocenyl or alkynyl Mo2Cp2(CO)4 and ferrocenyl, have been synthesised. NMR and IR studies of these cations show that the stabilising effects of the transition metal units are specific for each system. This situation implies different structures for the carbenium ions adjacent to two different organometallic moieties.

Cobalt and molybdenum carbonyl clusters in immunology. Synthesis and binding properties of mycotoxin derivatives of zearalenone

Abstract Transition metal cluster haptens of zearalenone derivatives having high binding affinity values for antibodies specific for this mycotoxin series have been synthesised. This provides the basis for a new type of non-isotopic immunoassay.

Synthesis, X-ray structure and chemical properties of 17α-ferrocenylestradiol

Abstract The X-ray structure of 17α-ferrocenylestradiol 1a shows that the ferrocenyl group is at the α position of the steroid, below the plane of the D ring. From acidic medium it is possible to obtain and isolate the derivative with a carbenium ion in 17-α position. This ion is transformed by various nucleophiles into the corresponding olefin 3 with CC at the C16C17 position. With NaBH 4 in acidic medium the reduction leads to a mixture of 17α- and 17β-ferrocenyl C 19 H 26 O 4a, 4b with a predominance of the β product, owing to a more favourable entrance of hydride in the α position. The oxidized derivative 17α-ferriciniumyl-estradiol tetrafluoroborate 5 was prepared and its are properties described.

Surprisingly facile decomposition of the dication : a metal-mediated Hunsdiecker reaction of a succinimidyl ester?

Abstract A series of dicationic organoiridium complexes [Cp * Ir(arene)] 2+ , ( 4 , 5 and 6 ) have been prepared in which the π-bonded phenyl ring is attached to an alkyl chain terminated by a succinimidyl ester, thus forming Bolton-Hunter reagents for protein labelling. In solution, the benzyl derivative, 4 , underwent facile decomposition. Loss of the succinimidyl moiety followed by decarboxylation led to [Cp * Ir(η-MeO C 6 H 4 Me)][BF 4 ] 2 ( 7 ). This product was characterized spectroscopically and by X-ray crystallography. Compound 7 crystallizes in the space group P2 1 /a with a = 13.567(5)A, b = 17.664(1)A, c = 9.044(5)A, β = 90.15°, V = 2167A 3 and Z = 4. A rationale for this surprisingly facile decomposition invokes stabilization of the intermediate benzyl radical by the iridium.

Régioselectivité de la propargylation, par des ions carbéniums organométalliques, d'aromatiques polysubstitués; application aux dérivés du zéranol

Abstract The selective attachment of propargyl Co 2 (CO) 6 groups at polysubstituted arene rings has been studied in zeranol, β-resorcylic acid and 6-methyl-β-resorcyclic acid series.

bis[Dichloro(η-pentamethylcyclopentadienyl)rhodium(III) and -iridium(III)] from bis[Chloro(1, 5-cyclooctadiene)rhodium(I) and -iridium(I)] Oxidation, and Formation of 1, 5-Cyclooctadiene(η-pentamethylcyclopentadienyl)rhodium(I)

Abstract An efficient and rapid alternative route for high yield (>90%) syntheses of [Cp∗MCl2]2 complexes (M = Rh, Ir) is described. This method involves the oxidation of M(I) to M(III) with HCl, from the commercially available [MCl(cod)]2 compounds (cod = 1, 5 cyclooctadiene). Repeating the above experiments for M =Rh but using Na2CO3 instead of HCl, afforded the known compound [Cp∗RhCod].