Carboxamide substituted tetramethylcyclopentadiene - synthesis, characterisation and its iridium(III) complex catalysed reduction of imines.

The novel dimeric iodo-iridium(III) complex, [Ir(Cp*CONMe2)I2]2, (Cp*CONMe2 = η5-N,N-2,3,4,5-hexamethylcyclopenta-2,4-diene carboxamide) bearing an amide moiety within the tetramethylcyclopentadiene ring, has been synthesised and characterised. The ligand Cp*CONMe2 is synthesised as two regioisomers, however the 2-substituted isomer exists as two distinguishable conformers due to restricted rotation about the amide carbonyl carbon and the ring carbon. The relative acidities of Cp*CONMe2 and Cp* are compared by their relative rates of H/D exchange. The iridium complex of N,N-2,3,4,5-hexamethylcyclopenta-2-4-diene carboxamide [IrCp*CONMe2] and (R,R)-1,2-diphenyl-N'-tosylethane-1,2-diamine ((R,R)-TsDPEN) has been evaluated in the transfer hydrogenation of imines under acidic conditions - a 5 : 2 molar ratio of formic acid : triethylamine as the hydride source for the transfer hydrogenation of 1-methyl-3,4-dihydroisoquinoline (DHIQ) and its 6,7-dimethoxy derivative in acetonitrile. A decreasing enantiomeric excess with reaction progress is attributed to different kinetic orders for formation of the two product amine enantiomers. The pseudo zero-order formation of the R-amine may be due to a pre-steady-state formation of the less stable form of the diastereomeric catalyst. By contrast, both enantiomeric amines from 1-fluorinated methyl DHIQs as substrates for reduction are formed by pseudo first-order processes.

[Case study of vulvar malignant melanoma conducted at the Cinquantenaire General Hospital in Lubumbashi]. / Mélanome malin vulvaire: à propos d'un cas observé à l'Hôpital du Cinquantenaire de Lubumbashi.

Primary malignant melanoma of the female genital tract is an extremely rare tumor. It most commonly affects the vulva then the cervix and the vagina. Vulvar cancer accounts for about 1% (all sites) of melanomas. In order of frequency, it occurs in the vagina, uterus and ovary. Less than 200 cases of vulvar cancers have been described worldwide. We here report a clinical case of malignant vulvar melanoma in a 72-year-old postmenopausal woman. Partial hemivulvectomy and bilateral superficial inguinal lymphadenectomy were performed. The postoperative course was favorable and the patient was discharged on postoperative day 15.

[Study of fetal heart rate abnormalities observed on cardiotocography in Lubumbashi: about a cases followed at the Lubumbashi University Clinic and the General Hospital of the Cinquantenaire]. / Etude des anomalies du rythme cardiaque fœtal observées à l'examen cardiotocographique à Lubumbashi: cas suivis aux Cliniques Universitaires de Lubumbashi et à l'Hôpital Général du Cinquantenaire Karavia.

Cardiotocography (CTG) has recently come into use in Lubumbashi but no thorough study has yet been conducted to identify its impact on perinatal morbi-mortality. This study aims to determine the frequency of fetal heart rate abnormalities (FHR)in order to identify the associated factors and to propose a suitable management. We conducted a cross-sectional, descriptive study of 411 women in labour over a period of 19 months (March 2015-December 2016). In patients with pathologic FHR abnormalities, sensitivity and positive predictive value of cardiotocography in the screening test for acute fetal distress were 82.95% and 45.35% respectively. FHR abnormalities were found in two women in labour out of five. Decelerations were the most frequent FHR abnormalities observed (50.8%) with a remarkable predominance of late decelerations (22.1% of all abnormalities). The factors associated with pathological FHR abnormalities were prolonged labor (OR = 14.64, CI = 3.91-54.81), chorioamnionitis (OR = 14.56, CI = 3.83-55.34), chronic maternal anemia (OR = 4.99, CI = 1.48-16.85), primiparity (OR = 2.69, CI = 1.49-4.85), prematurity (OR = 2.90, CI = 1.51-5.54) and prolonged pregnancy (OR = 3.22, CI = 1.38-7.52). Intrauterine growth retardation and arterial hypertension were mainly associated with flat lines and late decelerations (OR = 7.79, CI = 2.50-24.30 and OR=2.74, CI = 1.31-5.72). CTG is a screening tool for the identification of acute fetal distress but with high false-positive rate (55%); it should be associated with other second-line screening tests for acute fetal distress in order to reduce this rate. Factors associated with pathologic FHR abnormalities often cause acute fetal distress thus requiring a rigorous analysis of CTG traces.

The kinetics and mechanism of the organo-iridium catalysed racemisation of amines.

The dimeric iodo-iridium complex [IrCp*I2]2 (Cp* = pentamethylcyclopentadiene) is an efficient catalyst for the racemisation of secondary and tertiary amines at ambient and higher temperatures with a low catalyst loading. The racemisation occurs with pseudo-first-order kinetics and the corresponding four rate constants were obtained by monitoring the time dependence of the concentrations of the (R) and (S) enantiomers starting with either pure (R) or (S) and show a first-order dependence on catalyst concentration. Low temperature (1)H NMR data is consistent with the formation of a 1 : 1 complex with the amine coordinated to the iridium and with both iodide anions still bound to the metal-ion, but at the higher temperatures used for kinetic studies binding is weak and so no saturation zero-order kinetics are observed. A cross-over experiment with isotopically labelled amines demonstrates the intermediate formation of an imine which can dissociate from the iridium complex. Replacing the iodides in the catalyst by other ligands or having an amide substituent in Cp* results in a much less effective catalysts for the racemisation of amines. The rate constants for a deuterated amine yield a significant primary kinetic isotope effect kH/kD = 3.24 indicating that hydride transfer is involved in the rate-limiting step.