Triarylphosphines substituted with carboxylic and trifluoromethlyl groups have been prepared by the hydrolysis of trifluoromethyl groups using fuming sulfuric acid and boric acid. The reaction has ...been studied in a set of homoleptic and heteroleptic trifluoromethylated triarylphosphines and offers a new synthetic procedure for the preparation of carboxylic phosphines with a relatively simple methodology. The degree of carboxylation is modulated by the reaction conditions and is sensitive to the substitution pattern of the starting trifluoromethylated phosphines. A pH-dependent procedure based on the amphiphilic character of these phosphines was developed for their separation and purification. The electronic properties of the synthesized carboxylic-trifluoromethylated phosphines have been analyzed by
P NMR of the corresponding selenide derivatives. Finally, the structures of two palladium complexes, containing the
and
carboxylic-trifluoromethylated phosphines are also described, showing different dimeric structures.
Infection with Usutu virus (USUV) has been recently associated with neurologic disorders, such as encephalitis or meningoencephalitis, in humans. These findings indicate that USUV is a potential ...health threat. We report an acute human infection with USUV in France putatively associated with a clinical diagnosis of idiopathic facial paralysis.
The stereoelectronic properties of a series of trifluoromethylated aromatic phosphines have been studied using different approaches. The σ‐donating capability has been evaluated by nuclear magnetic ...resonance (NMR) spectroscopy of the selenide derivatives and the protonated form of the different trifluoromethylated phosphines. The coupling constants between phosphorous and selenium (1JSeP) and phosphorous and hydrogen (1JHP) can be predicted by empirical equations and correlate the basicity of the phosphines with the number and relative position of trifluoromethyl groups. In contrast, the π‐acceptor character of the ligands has been evaluated by measuring the frequency of the CO vibration in the infrared (IR) spectra of the corresponding Vaska type iridium complexes (IrCl(CO)(PAr3)2, PAr3=triarylphosphine). Moreover, the correlation between the electronic properties and the performance of these phosphines as ligands in the rhodium‐catalysed hydroformylation of 1‐octene has been established. Phosphines with the lowest basicity, that are those with the highest number of trifluoromethyl groups, gave rise to more active catalytic systems.
The σ‐donating and the π‐acceptor character of a series of trifluoromethylated phosphines have been evaluated using the selenide and phosphonium derivatives and the corresponding Vaska type iridium complexes (IrCl(CO)(PAr3)2, PAr3=triarylphosphine), respectively. The stereoelectronic properties have been correlated with the performance of these ligands in the rhodium catalysed hydroformylation of 1‐octene.
This article introduces a novel approach to payment innovations. It t identifies a cross-industry (retail trade and retail banking) and multi-country (USA, some Western European countries and Japan) ...approach to the interaction between these industries and the new retail payment systems from the 1970s to the mid 1990s. It documents and discusses the different trajectories that have been seen in the different competitive environments, particularly in regard to payment cards. It also analyses the involvement of bankers and retailers in the evolution of card payment systems and their contribution to the global adoption of bank cards. These processes have occurred within a framework in which sectoral boundaries have taken precedence over the payment alternatives associated with cross-industry solutions.
We aimed to analyze prognostic factors for relapse in stage I seminoma managed by either active surveillance or adjuvant chemotherapy, and to describe the long-term patterns of recurrence in both ...groups.
From 1994 to 2008, 744 patients were included in three consecutive, prospective risk-adapted studies by the Spanish Germ Cell Cancer Group. Low-risk patients were managed by surveillance and high-risk patients were given two courses of adjuvant carboplatin. Relapses were treated mainly with chemotherapy. Patient age, tumor size, histological variant, pT staging, rete testis invasion, and preoperative serum BHCG levels were assessed for prediction of disease-free survival (DFS).
After a median follow-up of 80 months, 63 patients (11.1%) have relapsed: 51/396 (14.8%) on surveillance and 12/348 (3.2%) following adjuvant carboplatin. Actuarial overall 5-year DFS was 92.3% (88.3% for surveillance versus 96.8% for chemotherapy, P = 0.0001). Median time to relapse was 14 months. Most recurrences were located at retroperitoneum (86%), with a median tumor size of 26 mm. All patients were rendered disease-free with chemotherapy (92%), radiotherapy (5%), or surgery followed by chemotherapy (3%). A nomogram was developed from surveillance patients that includes two independent, predictive factors for relapse: rete testis invasion and tumor size (as a continuous variable).
Long-term follow-up confirms the risk-adapted approach as an effective option for patients with stage I seminoma. The pattern of relapses after adjuvant chemotherapy is similar to that observed following surveillance. A new nomogram for prediction of DFS among patients on surveillance is proposed. Rete testis invasion and tumor size should be taken into account when considering the administration of adjuvant carboplatin. Prospective validation is warranted.
Enantiopure bis(diamidophosphite) ligands with a heterocyclic terminal fragment derived from (R)- and (S)-N,N′-dimethyl-1,1′-binaphthyldiamine and bridging fragments derived from ...(S,S)-2,3-butanediol (a), (4R,5R)-4,5-di(hydroxymethyl)-2,2-dimethyl-1,3-dioxolane (b), and (R)- and (S)-1,1′-bi-2-naphthol (c) were used to prepare the palladium complexes with general formula Pd(η3-2-CH3-C3H4)(P-P)X (X = PF6, 1a-(S;S al ,S al ;S), 1b-(R;R al ,R al ;R), 1b-(S;R al ,R al ;S), 1c-(R;R al ;R), 1c-(R;S al ;R); X = BPh4, 2a-(R;S al ,S al ;R), 2c-(R;R al ;R)), which have been fully characterized. The solid-state structure for complexes 1a-(S;S al ,S al ;S) and 1b-(R;R al ,R al ;R) has been determined by X-ray diffraction. The catalytic performance of the palladium complexes has been evaluated in asymmetric allylic alkylation and amination reactions with the benchmark substrate. The influence of the nature and absolute configuration of both the terminal and bridging fragments of the bis(diamidophosphite) ligands on the asymmetric induction is discussed. The best results in terms of enantioselectivity were obtained with 1c-(R;R al ;R), affording enantiomeric excesses up to 85% in both alkylation and amination reactions. A large match–mismatch effect between the absolute configurations of stereocenters of ligand c has been observed in the allylic amination process. Preliminary results in the rhodium-catalyzed asymmetric hydroformylation of styrene by using bis(diamidophosphite) ligands a, b, and c disclosed in all cases low enantiomeric discrimination for the branched aldehyde. Both for the allylic alkylation and for the hydroformylation reaction, a related monodentate diamidophosphite d, derived from (R)-N,N′-dimethyl-1,1′-binaphthyldiamine and (S)-borneol, was also tested. Palladium complexes of this monodentate ligand showed fairly good enantioselectivity in allylic alkylation, but with very low rate, while the rhodium complex of d rendered better enantioselectivity (37% ee) than the bidentate ligands a–c in the hydroformylation of styrene.
Background: Customizing chemotherapy on the basis of chemosentitivity prediction may improve outcome in advanced bladder cancer patients. Since DNA damaging agents are the cornerstones of therapy, we ...hypothesized that levels of DNA repair genes could predict survival. Patients and methods: Messenger RNA expression levels of excision repair cross complementing 1 (ERCC1), breast cancer 1 (BRCA1), ribonucleotide reductase subunit M1 (RRM1) and caveolin-1 were determined by RT-PCR in tumor DNA from 57 advanced and metastatic bladder cancer patients treated with either gemcitabine/cisplatin or gemcitabine/cisplatin/paclitaxel (Taxol). Levels were correlated with survival, time to disease progression and chemotherapy response. Results: Median survival was significantly higher in patients with low ERCC1 levels (25.4 versus 15.4 months; P = 0.03) (median follow-up 19 months). A trend towards longer time to progression was observed in patients with tumors expressing low levels of all markers. Levels of RRM1, BRCA1 and caveolin-1, however, failed to predict the survival and a clear link with chemotherapy response could not be established. On multivariate analysis with pretreatment prognostic factors, ERCC1 emerged as an independent predictive factor for survival. Conclusion: The results of the study indicate that ERCC1 may predict survival in bladder cancer treated by platinum-based therapy.
What type of crisis is generated when debt increases? We extend the literature by framework by introducing currency and stock market crises in the analysis. We apply our proposal to the case of ...Spain, since this is a country that has experienced a very important amount of financial crises from the nineteenth century onwards. We find the same results as the previous literature for the determinants of banking and debt crises but substituting external and public debt with perpetual debt and where perpetual debt has a less important role than crises in the private sector. Moreover, we find evidence in favour of the hypothesis that currency crises depend strongly and positively on financial centre crises and negatively and mildly on perpetual debt. We justify the negative relalionship due to an inflation tax. We also find evidence in favour of the hypothesis that stock market crises depend only positively and strongly on financial centre crises.
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