| 1. |
- Carroll, A. M., et al.
(författare)
-
Synthetic and mechanistic studies in enantioselective allylic substitutions catalysed by palladium complexes of a modular class of axially chiral quinazoline-containing ligands
- 2020
-
Ingår i: Tetrahedron. - : Elsevier BV. - 0040-4020. ; 76:1
-
Tidskriftsartikel (refereegranskat)abstract
- The application of palladium complexes of a modular series of axially chiral phosphinamine ligands, the Quinazolinaps, to the enantioselective alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate and methyl dimethyl malonate is described. Complete conversions and enantiomeric excesses of up to 91% were obtained. To elucidate the solution structure of these complexes and their dynamic behaviour, 2D COSY and NOESY NMR experiments were carried out. An X-ray crystal structure of a palladacycle derived from 2-phenylQuinazolinap which possesses two Pd3Cl5 units is shown. Computational studies were also undertaken to allow qualitative predictions of diastereomeric ratios. The observed enantioselectivity was then rationalised in terms of combined spectroscopic and theoretical data. The catalytic results obtained are best interpreted by the reaction proceeding with nucleophilic attack on the allyl trans to the phosphorus donor atom of the major diastereomeric intermediate. (C) 2019 Elsevier Ltd. All rights reserved.
|
|
| 2. |
|
|
| 3. |
- Ahlquist, Mårten, et al.
(författare)
-
Theoretical evidence for low-ligated palladium(0) : [Pd-L] as the active species in oxidative addition reactions
- 2006
-
Ingår i: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 25:8, s. 2066-2073
-
Tidskriftsartikel (refereegranskat)abstract
- The oxidative addition of PhI to Pd-O has been studied by DFT with a continuum representation of the solvent. It is shown that the preferred number of ligands on palladium is lower than would be expected from "conventional wisdom" and the 18-electron rule. The most favored oxidative addition is obtained when Pd is coordinated by only the aryl iodide and one additional ligand in a linear arrangement. The calculations indicate that p-orbitals on the central metal are not involved in bonding in any of the complexes described herein, in good agreement with classic ligand field theory and also with a recent bonding analysis by Weinhold and Landis, but in apparent violation of the 18-electron rule.
|
|
| 4. |
- Antonacci, G., et al.
(författare)
-
Manganese-Catalyzed Cross-Coupling of Aryl Halides and Grignard Reagents by a Radical Mechanism
- 2017
-
Ingår i: European Journal of Organic Chemistry. - : Wiley. - 1434-193X. ; :32, s. 4758-4764
-
Tidskriftsartikel (refereegranskat)abstract
- The substrate scope and the mechanism have been investigated for the MnCl2-catalyzed cross-coupling reaction between aryl halides and Grignard reagents. The transformation proceeds rapidly and in good yield when the aryl halide component is an aryl chloride containing a cyano or an ester group in the para position or a cyano group in the ortho position. A range of other substituents gave no conversion of the aryl halide or led to the formation of side products. A broader scope was observed for the Grignard reagents, where a variety of alkyl- and arylmagnesium chlorides participated in the coupling. Two radical-clock experiments were carried out, and in both cases an intermediate aryl radical was successfully trapped. The cross-coupling reaction is therefore believed to proceed by an S(RN)1 mechanism, with a triorganomanganate complex serving as the most likely nucleophile and single-electron donor. Other mechanistic scenarios were excluded based on the substrate scope of the aryl halide.
|
|
| 5. |
- Dominoni, Davide M., et al.
(författare)
-
Why conservation biology can benefit from sensory ecology
- 2020
-
Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 4:4, s. 502-511
-
Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic sensory pollutants, such as noise, light and chemicals, are affecting biodiversity. This Perspective uses an understanding of animal sensory ecology to explore how these impacts can be mitigated. Global expansion of human activities is associated with the introduction of novel stimuli, such as anthropogenic noise, artificial lights and chemical agents. Progress in documenting the ecological effects of sensory pollutants is weakened by sparse knowledge of the mechanisms underlying these effects. This severely limits our capacity to devise mitigation measures. Here, we integrate knowledge of animal sensory ecology, physiology and life history to articulate three perceptual mechanisms-masking, distracting and misleading-that clearly explain how and why anthropogenic sensory pollutants impact organisms. We then link these three mechanisms to ecological consequences and discuss their implications for conservation. We argue that this framework can reveal the presence of 'sensory danger zones', hotspots of conservation concern where sensory pollutants overlap in space and time with an organism's activity, and foster development of strategic interventions to mitigate the impact of sensory pollutants. Future research that applies this framework will provide critical insight to preserve the natural sensory world.
|
|
| 6. |
- Ellebæk, SB, et al.
(författare)
-
Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC)-directed treatment of peritoneal metastasis in end-stage colo-rectal cancer patients
- 2020
-
Ingår i: Pleura and peritoneum. - : Walter de Gruyter GmbH. - 2364-768X .- 2364-7671. ; 5:2, s. 20200109-
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundPressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC) represents a novel approach to intraperitoneal chemotherapy. Hereby results, obtained with PIPAC in patients with advanced peritoneal metastasis (PM) from colorectal cancer (CRC), are presented.MethodsData from CRC patients (n = 24) included in the prospective PIPAC-OPC1 and PIPAC-OPC2 trials are reported. Oxaliplatin 92 mg/m2 was administered at 4-6-week intervals. A CE certified nebulizer was used to aerosolize the chemotherapeutics. Outcome criteria were objective tumor response, survival and adverse events.ResultsRetrospective analysis of 74 PIPAC procedures carried out in 24 consecutive patients with PM from CRC included from October 2015 to February 2019. Five patients had still the primary tumor in situ, and 22 patients had received palliative systemic chemotherapy. Nineteen patients completed more than two PIPAC procedures, and objective tumor response according to the histological Peritoneal Regression Grading Score (PRGS) was observed in 67% of the patients, while 21% had stable disease. Four patients (21%) had complete response (mean PRGS = 1 and negative cytology). We recorded a median survival of 37.6 (range 7.3–48.9) months from the time of PM diagnosis, whereas it was 20.5 (range 0.13–34.7) months following the first PIPAC session. Minor postoperative complications were noted, and few were considered causally related to the PIPAC treatment. However, two cases of severe postoperative complications were recorded (urosepsis and iatrogenic bowel perforation).ConclusionsPIPAC with low-dose oxaliplatin can induce objective tumor regression in selected patients with advanced PM from colorectal cancer.
|
|
| 7. |
|
|
| 8. |
- Fristrup, Niels, et al.
(författare)
-
Cathepsin E, Maspin, Plk1, and Survivin Are Promising Prognostic Protein Markers for Progression in Non-Muscle Invasive Bladder Cancer
- 2012
-
Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 180:5, s. 1824-1834
-
Tidskriftsartikel (refereegranskat)abstract
- Bladder cancer is a common cancer with particularly high recurrence after transurethral resection. In this study, we investigated the prognostic value of the protein expression of cathepsin E, maspin, polo-like kinase 1 (Plk1), and survivin in patients with stage Ta and T1 urothelial carcinomas. Transcripts from the four genes encoding these proteins were previously included in gene expression signatures for outcome prediction for Ta/T1 bladder cancer. We used three different tissue microarrays with 693 non-muscle invasive urothelial carcinomas from Danish, Swedish, and Spanish patient cohorts with long-term follow-up. Protein expression was measured by immunohistochemistry, and antibody specificity was validated by Western blotting. In the Danish patient cohort, we found the expression of cathepsin E, maspin, Plk1, and survivin to be significantly associated with progression to stage T2 to T4 bladder cancer (for each marker: log-rank test; P < 0.001). Multivariate Cox regression analysis identified cathepsin E (P < 0.001), Plk1 (P = 0.021), maspin (P = 0.001), and survivin (P = 0.001) as independent prognostic markers. Furthermore, maspin, survivin, and cathepsin E expression significantly subgrouped patients already stratified by European Organization for Research and Treatment of Cancer risk scores. Finally, we successfully validated the results in tumors from 410 patients from both Sweden and Spain. We conclude that all four protein markers may have prognostic value in non-muscle invasive bladder cancer for guiding optimal treatment of patients. Additional prospective studies are needed for further validation of the clinical relevance of this marker panel.
|
|
| 9. |
- Fristrup, Niels, et al.
(författare)
-
Multicenter Validation of Cyclin D1, MCM7, TRIM29, and UBE2C as Prognostic Protein Markers in Non-Muscle Invasive Bladder Cancer
- 2013
-
Ingår i: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 182:2, s. 339-349
-
Tidskriftsartikel (refereegranskat)abstract
- Transcripts from the four genes encoding cyclin D1, MCM7, TRIM29, and UBE2C have previously been included in gene expression signatures for outcome prediction in stage Ta/T1 urothelial carcinomas. We investigated the prognostic value of the protein expressions in Ta/T1 urothelial carcinomas patients. We used four different tissue microarrays (TMAs) with a total of 859 Ta/T1 urothelial carcinomas from Danish, Swedish, Spanish, and Taiwanese patient cohorts with long-term follow-up. Protein expression was measured by IHC, and antibody specificity was validated by Western blotting. We found the expression of cyclin D1, MCM7, TRIM29, and UBE2C to be significantly associated with progression to muscle invasive bladder cancer (log-rank test; P < 0.001) in the Danish training cohort (n = 283). Multivariate Cox regression analysis identified cyclin D1 (P = 0.003), TRIM29 (P = 0.001), and UBE2C (P < 0.001) as independent prognostic markers. The prognostic value of the four proteins was validated in a joint validation cohort from Sweden, Spain, and Taiwan (n = 576). Computer-assisted image analysis of the prognostic markers produced results comparable to those obtained by manual scoring. Finally, a four-protein maximum-likelihood classifier was trained on the Danish training cohort and applied to the validation cohort. The four protein markers may help optimize treatment of patients with Ta/T1 bladder cancer. Additional prospective studies are needed for further validation of their clinical relevance.
|
|
| 10. |
|
|
