Synthesis of mono-, di- and tripalladated 1,3,5-benzenetristyryl complexes. CO insertion to give a dipalladated indenone.

The tribrominated arenes 1,3,5-C6(E-CHCHAr)3Br3 (Ar = Ph, (I), p-To (I')), add oxidatively to [Pd(dba)2] ([Pd2(dba)3]·dba) in the presence of two equivalents of a phosphine (PPh3 or PMe2Ph) to form the monopalladated complexes trans-[Pd{C6(E-CHCHAr)3Br2}Br(L)2] (Ar = Ph, L = PPh3 (1a), Ar = p-To, L = PPh3 (1a'), Ar = Ph, L = PMe2Ph (1b)), while the reaction in a 1 : 2 : 4 arene : Pd : PMe2Ph molar ratio affords the dipalladated complex [{trans-PdBr(PMe2Ph)2}2{µ2-C6(E-CHCHPh)3Br}] (2b). Both I and I' add oxidatively to 3 equivalents of [Pd(dba)2] in the presence of the chelating N-donor ligand tmeda (N,N,N',N'-tetramethylethylenediamine) to form the tripalladated complexes [{PdBr(tmeda)}3{µ3-C6(E-CHCHAr)3}] (Ar = Ph, (3c), p-To (3c')). Complex 3c reacts with PMe3 to form [{trans-PdBr(PMe3)2}3{µ3-C6(E-CHCHPh)3}] (3d). Compound 3c also reacts with CO to give the novel dipalladated indenone [2-Ph-4,6-{PdBr(tmeda)}2-5,7-(E-CHCHPh)2-inden-1-one] (4). The crystal structures of 1a' and 1b were determined by X-ray diffraction studies.

Dibromomethyl- and bromomethyl- or bromo-substituted benzenes and naphthalenes: C-Br...Br interactions.

The structures of six benzene and three naphthalene derivatives involving bromo, bromomethyl and dibromomethyl substituents, namely, 1,3-dibromo-5-(dibromomethyl)benzene, C7H4Br4, 1,4-dibromo-2,5-bis(bromomethyl)benzene, C8H4Br6, 1,4-dibromo-2-(dibromomethyl)benzene, C7H4Br4, 1,2-bis(dibromomethyl)benzene, C8H6Br4, 1-(bromomethyl)-2-(dibromomethyl)benzene, C8H7Br3, 2-(bromomethyl)-3-(dibromomethyl)naphthalene, C12H9Br3, 2,3-bis(dibromomethyl)naphthalene, C12H8Br4, 1-(bromomethyl)-2-(dibromomethyl)naphthalene, C12H9Br3, and 1,3-bis(dibromomethyl)benzene, C8H6Br4, are presented. The packing patterns of these compounds are dominated by Br...Br contacts and C-H...Br hydrogen bonds. The Br...Br contacts, shorter than twice the van der Waals radius of bromine (3.7 Å), seem to play a crucial role in the crystal packing of all these compounds. The occurrence of Type I and Type II interactions is also discussed briefly, considering the effective atomic radius of bromine, as is their impact on the packing of molecules in the individual structures.

Resident medical officers' redeployment experiences in the Adult Emergency Department during the COVID-19 pandemic at Te Toka Tumai | Auckland Hospital.

BACKGROUND: Te Toka Tumai Auckland Hospital enacted a multi-faceted plan in response to widespread community transmission of the Omicron variant of SARS-CoV-2 in 2022.1 This included redeploying a number of resident medical officers (RMOs) from other specialties to assist emergency medicine and general medicine services within the adult emergency department (AED). The purpose of this report is to evaluate the experience of the redeployed RMOs and identify ways to improve the redeployment process in the future. METHODS: An anonymous survey was sent out to the nineteen RMOs who were redeployed. Nine of 18 eligible RMOs responded (50%), with both quantitative and qualitative feedback collated. The quantitative data were descriptively compared, and a thematic analysis was performed. RESULTS: RMOs provided a range of responses about the redeployment experience, with 56% willing to be redeployed to the AED in a future crisis. Impact on training was the most commonly reported negative experience. Positive redeployment experiences related to feeling welcomed and appreciated, and to having the opportunity to enhance acute clinical skills. Areas for improvement included structured orientation, RMO input and consent in the redeployment planning process, and having a single point of communication between the RMOs being redeployed and the administration. CONCLUSION: The report identified areas of strength and areas for improvement in the redeployment process. Despite a small sample size, useful insights into the RMOs' experiences of being redeployed to acute medical services in the AED were gained.

A Widely Applicable and Versatile Method for the Ring-Opening 1,3-Carbocarbonation of Donor-Acceptor Cyclopropanes.

A 1,3-carbocarbonation of 2-substituted cyclopropane 1,1-dicarboxylates introduces various saturated or unsaturated carbon residues at the 1- and 3- position of the former three-membered ring. Under copper catalysis, ring-opening attack with a Grignard reagent proceeded smoothly; the intermediate was converted to the final product by reaction with appropriate carbon-based electrophiles under basic conditions. As nucleophiles, Grignard reagents derived from sp3 -, sp2 -, and sp-hybridized carbon residues were successfully employed, whereas various aliphatic bromides and EBX derivatives (for sp moieties) served as electrophiles.

Role of the Solvent in the Reactivity of Bis-4-imidazoline-2-selone Derivatives toward I2: An Experimental and Theoretical Approach.

The reactivity of 1,1'-bis(3-methyl-4-imidazolin-2-selone)methane (L1) and 1,2-bis(3-methyl-4-imidazolin-2-selone)ethane (L2) toward I2 has been explored in MeCN under different experimental conditions and compared with that in CH2Cl2. The compounds [L1'](I)2 (I), [L1I]n(I)n (II), [L1(µ-Se)](I)2·1/2H2O (III), [L1I](I3)·2I2 (IV), and [L2](I)2·MeCN (V) were obtained and characterized. X-ray diffraction analyses point out an ionic nature for these compounds, which is presumably favored by the polarity of the solvent used. In particular, [L1I]n(I)n (II) represents the first example of an iodonium complex of imidazoline-2-selone derivatives, while [L1(µ-Se)](I)2·1/2H2O (III) represents a unique example of a dicationic [RSeSeSeR] triselane. Density functional theory calculations have allowed us to better understand the nature of the obtained compounds and to justify their formations in polarizing reaction conditions rather than in low polar solvents.

Donor-Acceptor Cyclopropanes: Activation Enabled by a Single, Vinylogous Acceptor.

A novel class of highly activated donor-acceptor cyclopropanes bearing only a single, vinylogous acceptor is presented. These strained moieties readily undergo cycloadditions with aldehydes, ketones, thioketones, nitriles, naphth-2-ols and various other substrates to yield the corresponding carbo- and heterocycles. Diastereocontrol can be achieved through the choice of catalyst (Brønsted or Lewis acid). The formation of tetrahydrofurans was shown to be highly enantiospecific when chiral cyclopropanes are employed. A series of mechanistic and kinetic experiments was conducted to elucidate a plausible catalytic cycle and to rationalize the stereochemical outcome.

4-Amino-5-(4-bromo-benzo-yl)-3-(benzo[d]thia-zol-2-yl)-2-[(2',3',4',6'-tetra-O-acetyl-ß-d-galacto-pyran-osyl-)sulfanyl]-thio-phene.

In the title compound, C32H29BrN2O10S3, the benzo-thia-zole and thio-phene ring systems subtend an inter-planar angle of 7.43 (12)°. The NH2 group forms intra-molecular hydrogen bonds to Nthia-zole and Ocarbon-yl. The Sgalactose-Cthio-phene bond is short [1.759 (2) Å]. The mol-ecules are connected to form ribbons parallel to the b axis by two 'weak' hydrogen bonds and a short Namino⋯Sgalactose contact.

3-(Benzo[d]thia-zol-2-yl)-2H-chromen-2-one.

In the title compound, C16H9NO2S, the inter-planar angle is 6.47 (6)°. An intra-molecular S⋯O=C contact of 2.727 (2) Šis observed. The packing is determined by several types of weak inter-action ('weak' hydrogen bonds, S⋯S contacts and π-π stacking).

Crystal structure of 2-amino-5,6,7,8-tetra-hydro-7,7-dimethyl-4-(naphthalen-2-yl)-5-oxo-4H-chromene-3-carbo-nitrile.

In the title compound, C22H20N2O2, both six-membered rings of the fused heterocyclic system display envelope conformations; the two carbon atoms bearing the methyl groups and the naphthyl substituent both lie outside the planes of the other atoms of each ring. In the crystal, the amino group forms hydrogen bonds of the types N-H⋯O=C and N-H⋯N≡C, leading to the formation of a double layer structure propagating parallel to the bc plane. Weak C-H⋯O and C-H⋯π inter-actions may reinforce the layers.

Gold(I) metallocyclophosphazenes with antibacterial potency and antitumor efficacy. Synergistic antibacterial action of a heterometallic gold and silver-cyclophosphazene.

One of the most important uses of phosphazenes today involves its biomedical applications. They can also be employed as scaffolds for the design and construction of a variety of ligands in order to coordinate them to metallic drugs. The coordination chemistry of the (amino)cyclotriphosphazene ligand, [N3P3(NHCy)6], towards gold(I) complexes has been studied. Neutral complexes, [N3P3(NHCy)6{AuX}n] (X = Cl or C6F5; n = 1 or 2) (1-4), cationic complexes, [N3P3(NHCy)6{Au(PR3)}n](NO3)n (PR3 = PPh3, PPh2Me, TPA; n = 1, 2 or 3) (6-12) [TPA = 1,3,5-triaza-7-phosphaadamantane] and a heterometallic compound [N3P3(NHCy)6{Au(PPh3)}2{Ag(PPh3)}](NO3)3 (13) have been obtained and characterized by various methods including single-crystal X-ray diffraction for 7, which confirms the coordination of gold atoms to the nitrogens of the phosphazene ring. Compounds 1, 4, 6-13 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria. Both the median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) values are among the lowest found for any gold or silver derivatives against the cell lines and particularly against the Gram-positive (S. aureus) strain and the mycobacteria used in this work. Structure-activity relationships are discussed in order to determine the influence of ancillary ligands and the number and type of metal atoms (silver or gold). Compounds 4 and 8 showed not only maximal potency on human cells but also some tumour selectivity. Remarkably, compound 13, with both gold and silver atoms, showed outstanding activity against both Gram-positive and Gram-negative strains (nanomolar range), thus having a cooperative effect between gold and silver, with MIC values which are similar or lower than those of gentamicine, ciprofloxacin and rifampicine. The broad spectrum antimicrobial efficacy of all these metallophosphazenes and particularly of heterometallic compound 13 could be very useful to obtain materials for surfaces with antimicrobial properties that are increasingly in demand.

Crystal structure of 2-(benzo[d]thia-zol-2-yl)-3,3-bis-(ethyl-sulfan-yl)acrylo-nitrile.

In the title compound, C14H14N2S3, the double-bond system of the acrylo-nitrile moiety is significantly non-planar, with absolute cis torsion angles of 13.9 (2) and 15.1 (2)°. The ring system and the double bond system subtend an inter-planar angle of 11.16 (4)°. The wide angle C-C(CN)=C of 129.40 (12)° may be associated with a balance between planarity and avoidance of a very short S⋯S contact.

Crystal structure of 2-(2,5-di-meth-oxy-phen-yl)benzo[d]thia-zole.

The title compound, C15H13NO2S, was synthesized efficiently in the solid state by exploiting pepsin catalysis. The ring systems are nearly coplanar [inter-planar angle of 5.38 (2)°] with an associated intra-molecular S⋯O=C short contact of 2.7082 (4) Å. The packing involves C-H⋯O, C-H⋯π and π-π contacts.

Trends in computed tomography aortography and acute aortic syndrome in an emergency department within Aotearoa New Zealand.

OBJECTIVE: Acute aortic syndrome (AAS) comprises a triad of life-threatening aortic conditions that are difficult to diagnose because of their non-specific clinical presentations. Contrast-enhanced computed tomography aortography (CTA) has a high sensitivity and specificity for these conditions. However, under- and over-investigation of patients with suspected AAS using CTA carries significant risk. The aim of the present study was to evaluate the diagnostic imaging practices of CTA use for patients presenting to an ED with suspected AAS. METHODS: All atraumatic thoracic CTAs performed on patients aged ≥15 years old with suspected AAS who presented to Auckland City Hospital between 2009 and 2019 were included. Outcomes of interest were the annual ED and population incidences of AAS, and the rate of CTAs performed. RESULTS: A total of 1646 CTAs were included. There were 135 (8.2%) cases of at least one AAS diagnosis and 220 (13.4%) cases where an alternative diagnosis was made. The population-adjusted number of AAS diagnoses remained relatively stable over the study period, with a mean annual AAS incidence of 19.6 (95% confidence interval 9.9-33.7) per 100 000 patients, and 3.2 (95% confidence interval 1.6-5.4) per 100 000 population. The number of ED presentations increased during the study period, along with the population-adjusted rate of CTAs performed, from approximately 150 per 100 000 patients (2009) to 350 per 100 000 patients (2019). CONCLUSIONS: Thoracic CTA use for investigating suspected AAS in our ED has recently increased. However, the annual incidence of AAS did not increase over the same period, but was higher than reported in overseas institutions.

Insertion of S2 into Donor-Acceptor Cyclopropanes: Access to Dithiolanes and Their Conversion to Thietane Dioxides.

A facile and efficient route to dithiolanes starting from donor-acceptor cyclopropanes is reported. Potassium p-toluenethiosulfonate has been established as the reagent of choice for this formal insertion of the disulfide moiety. Using this methodology, dithiolanes have been synthesized in moderate to good yields with high functional group tolerance. Upon treatment with an excess of mCPBA, the corresponding dithiolanes delivered four-membered thietane dioxides, the formal (3+1)-cycloaddition product of D-A cyclopropanes, and sulfur dioxide.

Biomimetic Synthesis of Cyanogramides B and C.

Marinacarboline E and cyanogramides B and C from the marine-derived bacterium Actinoalloteichus cyanogriseus have been synthesized. The key step is the Baeyer-Villiger oxidation of marinacarboline E to a ketene aminal via O → N acetyl migration, followed by addition of water or MeOH. Replacing the phenylethyl by a styryl side chain afforded dehydromarinacarboline E that was oxidized to a tetracyclic aminal. This study contributes to the chemical understanding of the enzymatic conversions in the biosynthesis of the cyanogramides.

An Iterative Approach to Unsaturated and Partially Saturated [7]Helicenes.

We report a simple, iterative strategy for the synthesis of [7]helicenes starting from substituted 1,4-xylene building blocks. In the first step, we take advantage of the deprotonatable methyl groups to achieve ethano-bridged dimers. These are oxidatively coupled (without using metal-containing catalysts or light) using a hypervalent iodine reagent. Both steps are repeated to obtain the respective σ/π-helicenes. The degree of saturation can be controlled thermally during the oxidative coupling.

Ethnic Disparities in CT Aortography Use for Diagnosing Acute Aortic Syndrome.

Purpose: To determine whether CT aortography was performed in proportion to patient risk for acute aortic syndrome (AAS) and incidence of AAS for different ethnic groups. Materials and Methods: All atraumatic thoracic aorta CT aortographic examinations performed in adults (age > 15 years) suspected of having AAS between January 2009 and December 2019 at Auckland City Hospital (New Zealand) were included. Patients were risk stratified using the aortic dissection detection risk score (ADD-RS). The primary outcomes were the ratio of CT aortography rates to rates of positive CT aortographic examinations and the incidence of AAS. Population census data were used to determine age-standardized incidence of AAS in the emergency department (ED). Results: In total, 1646 CT aortographic examinations were performed in 1543 patients (mean age, 62 years ± 16 [SD]; 877 male patients). Maori (34% [68 of 203]) and Pacific Islanders (35% [80 of 229]) were more likely to be at high risk of AAS (ADD-RS > 1) compared with patients from other ethnic groups (25% [308 of 1214]); in the ED catchment population, age-standardized AAS incidence was significantly higher in Maori (6.9 per 100 000 person-years [95% CI: 4.3, 10.4]) and Pacific Islanders (5.3 [95% CI: 3.4, 7.8]) than in other ethnic groups (2.3 [95% CI: 1.8, 2.8]). Despite this higher incidence, disproportionately fewer CT aortographic examinations were requested in the ED for Maori (9.2 CT aortographic examinations per AAS diagnosis) and Pacific Islanders (9.2 CT aortographic examinations per AAS diagnosis) compared with other ethnic groups (13.8 CT aortographic examinations per AAS diagnosis). Conclusion: Maori and Pacific Islanders were at disproportionately higher risk of AAS but had fewer requested CT aortographic examinations compared with other ethnic groups. This increased risk of AAS in Pacific Islander and indigenous Maori patients should be considered by clinicians when investigating AAS.Keywords: Ethnicity, Maori, Pacific Islander, Aortic Dissection Detection Risk Score, Acute Aortic Syndrome, Aortic Dissection, CT Angiography Supplemental material is available for this article. © RSNA, 2022.

Crystal structures of the gold NHC complex bis-(4-bromo-1,3-di-ethyl-imidazol-2-yl-idene)gold(I) iodide and its 1:1 adduct with trans-bis-(4-bromo-1,3-diethyl-imidazol-2-yl-idene)di-iodido-gold(III) iodide.

The first title compound, [Au(C7H11BrN2)2]I, crystallizes in the space group P without imposed symmetry. The cations and anions are linked to form chains by Br⋯I⋯Br halogen-bond linkages. The second title compound, [Au(C7H11BrN2)2][AuI2(C7H11BrN2)2]I2, is an adduct of the first and its formally I2-oxidized AuIII analogue. It also crystallizes in space group P , whereby both gold atoms occupy inversion centres. The extended structure is a reticular layer involving Br⋯I⋯Br and I⋯I⋯Au linkages.

Crystal structure of 2-{[5-amino-1-(phenyl-sulfon-yl)-1H-pyrazol-3-yl]-oxy}-1-(4-methyl-phen-yl)ethan-1-one.

In the title compound, C18H17N3O4S, the pyrazole ring is planar, with the sulfur atom lying 0.558 (1) Šout of the ring plane. The NH2 group is involved in an intra-molecular hydrogen bond to a sulfonyl oxygen atom; its other hydrogen atom forms an asymmetric three-centre hydrogen bond to the two oxygen atoms of the -O-CH2-C=O- grouping, via the 21 screw axis, forming a ribbon structure parallel to the b axis. Translationally adjacent, coplanar ribbons form a layer parallel to (10).

Gold(I) and Gold(III) N-Heterocyclic Carbene Complexes as Antibacterial Agents and Inhibitors of Bacterial Thioredoxin Reductase.

A series of (NHC)Au(I)Cl monocarbene complexes and their gold(III) analogues (NHC)Au(III)Cl3 were prepared and investigated as antibacterial agents and inhibitors of bacterial TrxR. The complexes showed stronger antibacterial effects against the Gram-positive MRSA and E. faecium strains than against several Gram-negative bacteria. All complexes were efficient inhibitors of bacterial thioredoxin reductase, indicating that inhibition of this enzyme might be involved in their mechanism of action. The efficacy of gold(I) and gold(III) analogues was comparable in most of the assays. The cytotoxicity of the gold NHC compounds against cancer and human cells was overall weaker than the activity against the Gram-positive bacteria, suggesting that their optimization as antibacterials warrants further investigation.