Papers by Margarita Crespo
![Research paper thumbnail of Regioselective activation of CH bonds of naphthyl imines at platinum(II). Crystal structures of [PtMe{1-(2′-ClC6H4CH2NCH)C10H6}PPh3] and [PtMe{2-(2′-ClC6H4CH2NCH)C10H6}PPh3]](https://a.academia-assets.com/images/blank-paper.jpg)
Regioselective activation of CH bonds of naphthyl imines at platinum(II). Crystal structures of [PtMe{1-(2′-ClC6H4CH2NCH)C10H6}PPh3] and [PtMe{2-(2′-ClC6H4CH2NCH)C10H6}PPh3]
The reaction of [Pt2Me4(μ-SMe2)2] with ligands 1-(Me2NCH2CH2NCH)C10H7 (2a) and 2-(Me2NCH2CH2NCH)C... more The reaction of [Pt2Me4(μ-SMe2)2] with ligands 1-(Me2NCH2CH2NCH)C10H7 (2a) and 2-(Me2NCH2CH2NCH)C10H7 (2b) carried out in acetone at room temperature produced compounds [PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3a) and [PtMe2{1-(Me2NCH2CH2NCH)C10H7}] (3b), respectively, in which the imines act as bidentate [N,N′] ligands. Cyclometallated [C,N,N′] compounds [PtMe{1-(Me2NCH2CH2NCH)C10H6}] (4a) and [PtMe{2-(Me2NCH2CH2NCH)C10H6}] (4b) were obtained by refluxing toluene solutions of compounds 3a or 3b. Reaction of [Pt2Me4(μ-SMe2)2] with ligands 1-(2′-ClC6H4CH2NCH)C10H7 (2c) and 2-(2′-ClC6H4CH2NCH)C10H7 (2d) produced straightforward metallation to yield [PtMe{1-(2′-ClC6H4CH2NCH)C10H6}SMe2] (5c) and [PtMe{2-(2′-ClC6H4CH2NCH)C10H6}SMe2] (5d) containing a [C,N] ligand. Triphenylphosphine derivatives [PtMe{1-(2′-ClC6H4CH2NCH)C10H6}PPh3] (6c) and [PtMe{2-(2′-ClC6H4CH2NCH)C10H6}PPh3] (6d) were also prepared. All compounds were characterised by NMR spectroscopies and 6c and 6d were also characterised cry...
Luminescent Pt II and Pt IV Platinacycles with Anticancer Activity Against Multiplatinum‐Resistant Metastatic CRC and CRPC Cell Models
Chemistry – A European Journal
Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide v... more Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide variety of tumours. Nevertheless, the acquisition of platinum resistance is utterly common, ultimately cornering conventional platinum drugs to only palliative in many patients. Thus, encountering alternatives that are both effective and non-cross-resistant is urgent. In this work, we report the synthesis, reduction studies and luminescent properties of a series of cyclometallated (C,N,N') PtIV compounds derived from amine-imine ligands, and their remarkable efficacy at the high nanomolar range and complete lack of cross-resistance, as an intrinsic property of the platinacycle, against multiplatinum-resistant colorectal cancer (CRC) and castration-resistant prostate cancer (CRPC) metastatic cell lines generated for this work. We have also determined that the compounds are effective and selective for a broader cancer panel, including breast and lung cancer. Additionally, selected compounds have been further evaluated, finding a shift in their antiproliferative mechanism towards more cytotoxic and less cytostatic than cisplatin against cancer cells, being also able to oxidize cysteine residues and inhibit topoisomerase II, thereby holding great promise as future improved alternatives to conventional platinum drugs.
New Journal of Chemistry
New [C,N,N′]-cyclometallated platinum(ii) and platinum(iv) complexes are prepared and their emiss... more New [C,N,N′]-cyclometallated platinum(ii) and platinum(iv) complexes are prepared and their emission properties are reported.
Synthesis, characterization and biological activity of new cyclometallated platinum(iv) iodido complexes
Dalton Transactions
Six novel cyclometallated platinum(iv) iodido complexes are prepared and their cytotoxic activity... more Six novel cyclometallated platinum(iv) iodido complexes are prepared and their cytotoxic activity against a panel of human adenocarcinoma is reported.
Synthesis, characterization and biological activity of new cyclometallated platinum(iv) complexes containing a para-tolyl ligand
Dalton Transactions
Synthesis and biological activity of cyclometallated platinum(iv) compounds containing a para-tol... more Synthesis and biological activity of cyclometallated platinum(iv) compounds containing a para-tolyl ligand are reported.
On the stability and biological behavior of cyclometallated Pt(IV) complexes with halido and aryl ligands in the axial positions
Bioorganic & Medicinal Chemistry, 2016
A series of cyclometallated platinum(IV) compounds (3a, 3a&am... more A series of cyclometallated platinum(IV) compounds (3a, 3a' and 3b') with a meridional [C,N,N'] terdentate ligand, featuring an halido and an aryl group in the axial positions has been evaluated for electrochemical reduction and preliminary biological behavior against a panel of human adenocarcinoma (A-549 lung, HCT-116 colon, and MCF-7 breast) cell lines and the normal bronquial epithelial BEAS-2B cells. Cathodic reduction potentials (shifting from -1.463 to -1.570V) reveal that the platinum(IV) compounds under study would be highly reluctant to be reduced in a biological environment. Actually ascorbic acid was not able to reduce complex 3a', the most prone to be reduced according its reduction potential, over a period of one week. These results suggest an intrinsic activity for the investigated platinum(IV) complexes (3a, 3a' and 3b'), which exhibit a remarkable cytotoxicity effectiveness (with IC50 values in the low micromolar range), even greater than that of cisplatin. The IC50 for A-549 lung cells and clog P values were found to follow the same trend: 3b'>3a'>3a. However, no correlation was observed between reduction potential and in vitro activity. As a representative example, cyclometallated platinum(IV) compound 3a', exercise its antiproliferative activity directly over non-microcytic A-549 lung cancer cells through a mixture of cell cycle arrest (13% arrest at G1 phase and 46% arrest at G2 phase) and apoptosis induction (increase of early apoptosis by 30 times with regard to control). To gain further insights into the mode of action of the investigated platinum(IV) complexes, drug uptake, cathepsin B inhibition and ROS generation were also evaluated. Interestingly an increased ROS generation could be related with the antiproliferative activity of the cyclometallated platinum(IV) series under study in the cisplatin-resistant A-549 lung and HCT-116 cancer cell lines.
Organometallics, 1987
Supplementary Material Available: Tables of crystal data, fractional atomic coordinates, thermal ... more Supplementary Material Available: Tables of crystal data, fractional atomic coordinates, thermal parameters, and interatomic distances and angles for 1 (9 pages); a listing of observed and calculated structure factors for 1 (11 pages). Ordering information is given on any current masthead page. [ (C6Me6)RuC12]Z, 67421-02-7.
Oxidative addition of methyl iodide to dimethylplatinum (II) compounds containing bulky and/or chiral ligands. Crystal structure of compound [PtMe 3I{1-(Me 2NCH 2 CH 2NCH)C 10H 7}]
Polyhedron, 2003
Compound [PtMe2{1-(Me2NCH2CH2NCH)C10 H7}] (2a) gave upon reaction with methyl iodide platinum (IV... more Compound [PtMe2{1-(Me2NCH2CH2NCH)C10 H7}] (2a) gave upon reaction with methyl iodide platinum (IV) compound [PtMe3I{1-(Me2NCH2CH2NCH)C10H7}] (3a) as a single isomer which was characterised structurally. Upon standing in solution, two isomers of 3a were detected by 1H NMR. New chiral compounds [PtMe2(N,N′-chelate)] (N,N′=2-((S)-CHNCH(Me)C6H5)C9H6N (2b), 2-((R)-CHNCH(Me)C10H7)C5H4N (2c) and 2-((R)-CHNCH(Me)C10H7)C9H6N (2d)) were obtained from [Pt2Me4(μ-SMe2)2] and the corresponding diimines. The oxidative addition of methyl
Intramolecular activation of a C?F bond at platinum(II) in the presence of weaker C?X bonds (X = H, Cl and Br)
Journal of the Chemical Society Chemical Communications, 1992
ABSTRACT
![Research paper thumbnail of Cyclometallated platinum compounds with N-benzylidenebenzylamines bearing trifluoromethyl groups. Crystal structure of [PtMe?3-(CF3) C6H3CH==NCH2Ph?(PPh3)]](https://attachments.academia-assets.com/75406653/thumbnails/1.jpg)
Polyhedron, 1998
The reaction of [Pt2Me4(p-SMe2)2] (1) with the imine 3-(CF3)C6H4CH-NCH2Ph (2a) yields the cyclome... more The reaction of [Pt2Me4(p-SMe2)2] (1) with the imine 3-(CF3)C6H4CH-NCH2Ph (2a) yields the cyclometallated compound [PtMe{3-(CF3)C6H3CH-NCH2Ph}(SMe2)] (3a) by selective metallation at the less hindered of the two ortho positions of the aryl ring followed by loss of methane. A similar reaction for imine 2-(CF3)C6H4CH-NCH2Ph (2c) yields the cyclometallated compound [PtMe{2-(CF3)C6H3CH-NCH2Ph} (SMe2)] (3c). The reactions of these compounds with triphenylphosphine in (1 : 1) ratio produce compounds [PtMe{3-(CF3)C6H3CH-NCH2Ph}(PPh3)] (4a) and [PtMe{2-(CF3)C6H3CH-NCH2Ph}(PPh3)] (4c). The Xray structure of 4a is reported. An excess of triphenylphosphine produces metallacycle cleavage and [PtMe{3-(CF3)C6H3CH-NCHzPh}(PPh3)2] (5a) is formed with the imine acting as a [C-] unidentate ligand. Oxidative addition of methyl iodide to compounds 4a and 4c gives cyclometallated platinum(IV) complexes. Imines 3,5-(CF3)2C6H3CH=NCH2Ph (2b) and 2-F-6-(CF3)C6H3CH=NCH2Ph (2d) fail to react with [Pt2Mea(#-SMe2)2] (1).
Steric and electronic effects on the regioselective formation of platinum(II) metallacycles: crystal structure of [PtMe(3-MeC 6H 3CHNCH 2C 6H 5)(PPh 3)]
J Organomet Chem, 1996
... 3.1. Preparation of the conpounds The complex [PtaMe(IxSMe)] (1) was prepared by the method r... more ... 3.1. Preparation of the conpounds The complex [PtaMe(IxSMe)] (1) was prepared by the method reported in the literature [17]. 3. Experlmen SH and tP 'H NMR spectra were recorded using Van Gemini 200 (SH; 200 MHz). Broker ...
Monohydrido-bridged platinum(II)?gold(I) complexes. X-Ray crystal structure of [(Ph3P)2(C6Cl5)Pt(�-H)Au(PPh3)]ClO4�2Et2O
J Chem Soc Dalton Trans, 1989
ABSTRACT
Synthesis and reactivity of cyclometallated platinum (II) compounds containing [C,N,N′] terdentate ligands: Crystal structures of [PtCl{(CH 3) 2N(CH 2) 3NCH(4-ClC 6H 3)}], [PtCl{(CH 3) 2N(CH 2) 3NCH(2-ClC 6H 3)}] and [PtCl{(CH 3) 2N(CH 2) 3NCH(3-(CH 3)C 6H 3)}]
J Organomet Chem, 2005
Reactivity and mechanism in the formation of (.mu.-hydrocarbyl)diplatinum(IV) complexes by oxidative addition of .alpha.,.alpha.'-dibromoxylenes to dimethylplatinum(II) complexes
Organometallics, 1987
... 32-9. Reactivity and Mechanism in the Formation of ... Models show that 14 can undergo intram... more ... 32-9. Reactivity and Mechanism in the Formation of ... Models show that 14 can undergo intramolecular oxidative addition by the SN2 mechanism to give 15 (Scheme 111), and this reaction is clearly much faster than the rate of formation of 14. ...
Journal of Organometallic Chemistry, Apr 7, 1987
Effects of chlorine substituents upon the formation, reactivity and electrochemical properties of platinum(II) and platinum(IV) metallacycles
Journal of Organometallic Chemistry, 1998
Following our interest in cyclometallated platinum(II) and platinum(IV) complexes, containing ter... more Following our interest in cyclometallated platinum(II) and platinum(IV) complexes, containing terdentate [C,N,N′] [2, 3, 4] or bidentate [C,N] [5, 6] ligands, we now report the synthesis, reactivity and electrochemical properties of new compounds obtained by the reaction of [Pt 2 Me 4 ...
Reactivity and mechanism in the formation of (m-hydrocarbyl)diplatinum(IV) complexes by oxidative addition of a,a'-dibromoxylenes to dimethylplatinum(II) complexes
Organometallics
ABSTRACT
Dalton transactions (Cambridge, England : 2003), Jan 3, 2015
The synthesis and preliminary biological evaluation of neutral and cationic platinum derivatives ... more The synthesis and preliminary biological evaluation of neutral and cationic platinum derivatives of chiral 1-(1-naphthyl)ethylamine are reported, namely cycloplatinated neutral complexes [PtCl{(R or S)-NH2CH(CH3)C10H6}(L)] [L = SOMe2 ( or ), L = PPh3 ( or ), L = P(4-FC6H4)3 (), L = P(CH2)3N3(CH2)3 ()], cycloplatinated cationic complexes [Pt{(R)-NH2CH(CH3)C10H6}{L}]Cl [L = Ph2PCH2CH2PPh2 (), L = (C6F5)2PCH2CH2P(C6F5)2 ()] and the Pt(ii) coordination compound trans-[PtCl2{(R)-NH2CH(CH3)C10H6}2] (). The X-ray molecular structure of is reported. The cytotoxic activity against a panel of human adenocarcinoma cell lines (A-549 lung, MDA-MB-231 and MCF-7 breast, and HCT-116 colon), cell cycle arrest and apoptosis, DNA interaction, topoisomerase I and cathepsin B inhibition, and Pt cell uptake of the studied compounds are presented. Remarkable cytotoxicity was observed for most of the synthesized Pt(ii) compounds regardless of (i) the absolute configuration R or S, and (ii) the coordinated/...
Cyclometallated platinum compounds with chiral imines. Crystal structure of [PtMe(2-FC6H3CHN-(S)-CHMePh)(PPh3)]
Polyhedron, 1999
ABSTRACT
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Papers by Margarita Crespo