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A 60–year–old woman presented to the emergency department with acute left hemiplegia, not chest pains. Past medical history was significant for family history of aortic aneurysm, arterial hypertension. At brain–CT was reported hypodensity areas in posterior arm of the right internal capsule and in right tempero–polar lobe, confirmed on brain–MRI, and compatible with acute ischemic injury. Echocolor–dopper of epiaortic vessels documentated ulcerated plaque into the right common carotid artery (CCA). Selective catheterization found focal dissection obstructing the flow, treated with self–expanding stent. On echocardiography evalutation for suspiction of TAAD: dilatation of ascending aorta with flap oscillation, severe arotic regurgitation, pericardial effusion (Fig. 1). CT–Angiography was performed with evidence of type A dissection extending superiorly to the right CCA and inferiorly to the iliac bifurcation. For coma state, the patient was mechanically ventilated, and seriate CTs showed new ischemic lesions and hemorrhagic infarction of previous. Because of contraindication for cardiac surgery due neurological state, the patient was referred at medical therapy as bridge to hybrid aortic arc substitution at resolution of intracranial hemorrhages. In the next days there was progressive improvement neurological status with restoration of sensory and autonomic breathing with hemodynamic stability. Aortic dissection (AD) is defined as a disruption of the medial layer leading to the formation of two lumens separated by an intimomedial flap. AD is a critical diagnosis to make due to life–threatening outcomes and its non–specific presentation as in the case of our patient where the management of AD was delayed due to an unusual initial clinical presentation. Multimodality imaging approach has been fundamental for correct diagnosis and risk stratification. A limited number of studies have reported cases with stroke as the first symptom with concomitant TAAD. Concomitant intracerebral hemorrhage and TAAD is a very rare presentation and the optimal timing of surgery in these patients is unknown. In our opinion, patients who presents acute stroke should be carefully evaluated using multimodal imaging to exclude TAAD before administering reperfusion therapy. In addition, performing CAS before surgery for TAAD is challenging but might be a valid treatment option to maintain good brain perfusion and improve prognosis, but further investigations are needed.

A new class of platinum(II) compounds of the formula [PtMe(olefin)(N,N‘-imino−amide chelate)] is described (olefin = ethylene, propylene, styrene, allyl alcohol, methyl vinyl ketone, methyl acrylate; N,N‘-imino−amide chelate = N,N‘-(1,2-dimethyl-1,2-ethanediylidene)bis(2,6-diisopropylaniline)). The neutral complexes exhibit square-planar coordination with a cis arrangement of the olefin and the alkyl group. The compounds have been characterized through one- and two-dimensional NMR spectroscopy, which has disclosed that only one isomer is present in solution. This isomer exhibits the alkene and the N(amido) atom in trans positions, while the alkene substituent is oriented toward the Pt−Me vector. The nature and the arrangement of the ligands seem suitable to favor a π-back-donation contribution to the Pt−olefin bond to an extent unprecedented for square-planar compounds, as discussed on the basis of NMR parameters and theoretical calculations.

The oxidative addition of RE−ER molecules (E = O, R = H, C(O)Ph, C(O)Me; E = S, Se, Te, R = Me, Ph) to Pt(0) precursors [Pt(N,N-chelate)(olefin)] (1:  N,N-chelate = e.g. 2,9-dimethyl-1,10-phenanthroline; olefin = maleic or fumaric ester) has been studied. Symmetrical cleavage of the E−E bonds affords unprecedented trigonal-bipyramidal Pt(II) complexes of the formula [Pt(ER)2(N,N-chelate)(olefin)] (2). Products of type 2, which have been characterized through ¹H and ¹³C NMR spectroscopy, contain chalcogenide ligands in the axial positions. The reactivity of the new compounds has also been investigated. Thus, Pt−OH fragments generated by the addition of H2O2 are acetylated by acetic anhydride. Furthermore, S, Se, and Te coordinated to Pt are readily methylated by trimethyloxonium tetrafluoroborate, affording the first examples of dipositive coordinatively saturated platinum(II) cations (3). The structures of the related neutral [Pt(SMe)2(2,9-dimethyl-1,10-phenanthroline)(diphenyl fumarate)] and cationic [Pt(SMe2)2(2,9-dimethyl-1,10-phenanthroline)(diphenyl fumarate)][BF4]2 compounds have been determined by X-ray diffraction together with that of the free diphenyl fumarate ligand.

The relative cation−anion position in [Pt(Me)(η²-olefin)(N,N)]BF4 complexes (where N,N = 2,6-(R‘)2C6H3N&dbd;C(R‘ ‘)C(R‘ ‘)&dbd;N-2,6-(R‘)2C6H3, R‘ = H, Me, Et, and i-Pr, R‘ ‘ = H, Me; olefin = CH2&dbd;CHR, R = H, Me, COOMe) in methylene chloride has been investigated by detecting specific interionic dipolar interactions in the ¹⁹F{¹H}-HOESY NMR spectra. The counterion shows strong interionic contacts with R‘ ‘ and R‘ protons and weak contacts with R and olefinic protons only when R‘ < Et and R‘ ‘ = Me. For R‘ ≥ Et the accessibilty to the metal center is completely inhibited and the counterion is located above or below the backside of the diimine ligand. The same position is also observed when R‘ ‘ = H and R‘ = R = Me despite the limited steric hindrance of the substituents due to specific interactions between H‘ ‘ and the fluorine of BF4^-. In the other cases (R‘ < Et), the counterion also interacts with Me, R, and olefinic protons, indicating that the accessibility to the metal center is not forbidden.

Coordinatively saturated carbene complexes of platinum(II) have been obtained by oxidative addition of [ClCH&dbd;NMe2]Cl to Pt(0) precursors. The cationic products of general formula [PtCl(CHNMe2)(N,N-chelate)(olefin)]Cl have been characterized through NMR spectroscopy and for [PtCl(CHNMe2)(2,9-Me2-1,10-phen)(Z-MeO2CCH&dbd;CHCO2Me)]Cl by X-ray diffractometry. The latter species reacts with nucleophiles affording dimethylformamide and the corresponding Pt(0) precursor [Pt(2,9-Me2-1,10-phen)(Z-MeO2CCH&dbd;CHCO2Me)]. Attempts to obtain related complexes containing carbene groups Pt&dbd;CHY without a heteroatom in α-position (Y = CO2Et, CO2NMe2, CN) have led to the isolation of complexes of formula [PtR(dmphen){η¹,η²-CH(Y)O2CCH&dbd;CHCO2Me}] (R = Me, Ph), formally derived from an intramolecular nucleophilic addition to a carbene intermediate. The X-ray structure of a representative product, [PtMe(dmphen){η¹,η²-CH(CO2Et)O2CCH&dbd;CHCO2Me}], is reported.