Selective Metal-Free Hydrosilylation of CO2 Catalyzed by Triphenylborane in Highly Polar, Aprotic Solvents.

Triphenylborane (BPh3 ) in highly polar, aprotic solvents catalyzes hydrosilylation of CO2 effectively under mild conditions to provide silyl formates with high chemoselectivity (>95 %) and without over-reduction. This system also promotes reductive hydrosilylation of tertiary amides as well as dehydrogenative coupling of silane with alcohols.

Bis(cyclopropenium)phosphines: Synthesis, Reactivity, and Applications.

A straightforward route for the preparation of a set of bis(cyclopropenium)-substituted phosphines is reported. Due to their dicationic nature, these ligands depict an excellent π-acceptor character. The effect of the ligand substituent pattern on the catalytic activity of the metal complexes thereof derived is also studied. Whereas sterically demanding biaryl groups directly attached to the phosphorus atom seem to facilitate elementary steps such as the product release from the catalyst, long chain dialkylamino groups on the cyclopropenium units maximize the catalysts solubility and, thus, allow the use of typical apolar solvents such as toluene. Importantly, all new ligands prepared can be easily handled in air. Finally, the impact of the newly prepared dicationic phosphines in hydroarylation reactions is demonstrated. In particular, their use in the synthesis of several naphtho[1,2-b]furanes and naturally occurring naphthalene derivatives such as Calanquinone C is reported.

A cationic zinc hydride cluster stabilized by an N-heterocyclic carbene: synthesis, reactivity, and hydrosilylation catalysis.

The trinuclear cationic zinc hydride cluster [(IMes)3Zn3H4(THF)](BPh4)2 (1) was obtained either by protonation of the neutral zinc dihydride [(IMes)ZnH2]2 with a Brønsted acid or by addition of the putative zinc dication [(IMes)Zn(THF)](2+). A triply bridged thiophenolato complex 2 was formed upon oxidation of 1 with PhS-SPh. Protonolysis of 1 by methanol or water gave the corresponding trinuclear dicationic derivatives. At ambient temperature, 1 catalyzed the hydrosilylation of aldehydes, ketones, and nitriles. Carbon dioxide was also hydrosilylated under forcing conditions when using (EtO)3SiH, giving silylformate as the main product.

Transphyseal distal humeral separation in neonates: A case series.

INTRODUCTION: Birth trauma is a rare condition. Typically, injury in neonates occurs as a result of obstetrical manipulation to allow delivery or from trauma sustained during a difficult passage through the birth canal. Transphyseal separation of the humerus is particularly rare. Diagnosis is not always straightforward and is prone to mistakes. There is a general consensus that the outcome is usually favorable. It is generally agreed that the fracture needs to be realigned, while the suggested methods in contention vary from a simple plaster cast to closed and even open reduction and percutaneous Kirschner wire fixation. The purpose of this study was to review our experience in treating transphyseal distal humeral separation in neonates to better define the diagnostic and therapeutic pathway. METHODS: Ten consecutive cases of transphyseal distal humeral separation in neonates were treated at our institution between September 2008 and June 2021. All cases were reviewed and clinical data collected on birth injury risk factors, diagnostic workup, age at diagnosis and treatment, and type of treatment. Results of treatment and outcome were analyzed for time to fracture union, complications and clinical alignment, range of motion and residual pain at the latest follow-up. RESULTS: Mean age at diagnosis was 4.2 days (range 0 to 9 days) and time between diagnosis and treatment varied from three to 26 h (average 15 h). Risk factors for birth injury were present in six patients. Four patients were initially treated with closed reduction and cast immobilization, all the other cases were treated with closed reduction and percutaneous pinning. Arthrography was performed at the time of treatment in six cases. Average follow-up was 37 months (range 12 to 120 months). At the latest follow-up, all fractures had healed with full range of motion. No clinical or radiographic deformity requiring repeated surgery or physeal damage was observed. CONCLUSIONS: This rare lesion may occur both in the presence and in the absence of risk factors. Due to the rarity of the injury, misdiagnosis and delayed diagnosis are not uncommon. Treatment with closed reduction and percutaneous pin fixation is advisable and safe.

Bioactive glass in the treatment of chronic osteomyelitis in children: Description of four consecutive cases and literature review.

INTRODUCTION: Chronic osteomyelitis in children is a rare condition. Debridement surgery, along with appropriate antibiotic therapy, is widely agreed to represent the best procedure in the treatment of chronic osteomyelitis but can result in an extensive dead space formation. In this study, we evaluated the use of bioactive glass to address dead space management. METHODS: Four consecutive cases of chronic osteomyelitis treated with antibiotic therapy, one stage- surgical debridement and bioglass implantation between September 2016 and February 2017 were prospectively followed for a minimum of three years. Two cases followed acute hematogenous osteomyelitis, two cases followed fracture fixation. Clinical, histology, laboratory and radiographic findings were recorded. Primary endpoint was eradication of infection. Possible complication related to bioglass application were investigated. RESULTS: All patients achieved healing at the latest follow-up of minimum three years. No successive surgical treatments were required at any time. No complications related to the bioglass were detected. Radiographic reconstruction of normal anatomy progressed through the years. CONCLUSIONS: Bioglass for the treatment of dead space after surgical debridement appears a viable option in the treatment of chronic osteomyelitis in children.

Direct cupration of fluoroform.

We have found the first reaction of direct cupration of fluoroform, the most attractive CF(3) source for the introduction of the trifluoromethyl group into organic molecules. Treatment of CuX (X = Cl, Br, I) with 2 equiv of MOR (M = K, Na) in DMF or NMP produces novel alkoxycuprates that readily react with CF(3)H at room temperature and atmospheric pressure to give CuCF(3) derivatives. The CuCl and t-BuOK (1:2) combination provides best results, furnishing the CuCF(3) product within seconds in nearly quantitative yield. As demonstrated, neither CF(3)(-) nor CF(2) mediate the Cu-CF(3) bond formation, which accounts for its remarkably high selectivity. The fluoroform-derived CuCF(3) solutions can be efficiently stabilized with TREAT HF to produce CuCF(3) reagents that readily trifluoromethylate organic and inorganic electrophiles in the absence of additional ligands such as phenanthroline. A series of novel Cu(I) complexes have been structurally characterized, including K(DMF)[Cu(OBu-t)(2)] (1), Na(DMF)(2)[Cu(OBu-t)(2)] (2), [K(8)Cu(6)(OBu-t)(12)(DMF)(8)(I)](+) I(-) (3), and [Cu(4)(CF(3))(2)(C(OBu-t)(2))(2)(µ(3)-OBu-t)(2)] (7).

One-pot preparation of imines from nitroarenes by a tandem process with an Ir-Pd heterodimetallic catalyst.

A new tandem catalytic process has been studied for a heterodimetallic complex containing both iridium and palladium fragments connected by a 1,2,4-trimethyltriazolyldiylidene ligand. The process implies the unprecedented preparation of imines from the direct reaction of nitroarenes and primary alcohols. The global process comprises the following steps: 1) reduction of the nitroarene to an amine, 2) oxidation of the alcohol to aldehyde, and 3) condensation of the aldehyde and the amine to form the corresponding imine. The oxidation of the alcohol to aldehyde is promoted by the iridium fragment, while the reduction of the nitro group to amine is facilitated by palladium. A wide set of different catalytic systems has been studied, showing that the Ir/Pd complex 1 is a highly active and stable catalyst in the preparation of imines.

An Ir-Pt catalyst for the multistep preparation of functionalized indoles from the reaction of amino alcohols and alkynyl alcohols.

The 1,2,4-trimethyltriazolylidene (ditz) ligand allows the preparation of homo- and heterodimetallic complexes of Pt(2) and Ir-Pt. These two complexes have been characterized by means of spectroscopic and diffractommetric techniques. The catalytic activity of these complexes, together with that of other Pt-based compounds, has been explored in the cyclization-addition of alkynyl alcohols and indoles. The Ir-Pt complex [{PtI(2)(py)}(µ-ditz){IrI(2)(Cp*)}] (py=pyridine; Cp*=pentamethylcyclopentadienyl) allows the combination of an iridium-mediated oxidative cyclization of 2-(ortho-aminophenyl)ethanol to form indoles, with a further step employing a Pt-based multistep reaction that functionalizes indoles. Our results show that the Ir-Pt complex is a very active catalyst in this new multistep preparation of functionalized indoles from the reaction of an amino alcohol with alkynyl alcohols.

The influence of laterality, sex and family history on clubfoot severity.

PURPOSE: Epidemiological studies on idiopathic clubfeet have shown a typical distribution consistent across ethnic groups: bilaterality in about 50% of cases and a male to female ratio of 2:1. Whether this corresponds also to differences in severity according to laterality and sex has been poorly evaluated. As well, the correlation between family history and severity has not been previously investigated. The aim of this study was to investigate how laterality, sex and family history influence severity and treatment. METHODS: In all, 97 infants with idiopathic clubfoot (81 male, 16 female; 55 unilateral, 42 bilateral; 19 with a first or second-degree relative affected) consecutively treated with Ponseti method were prospectively enrolled. Initial severity (according to Dimeglio and Pirani scores) and treatment (number of casts and need for tenotomy) were analyzed in the different subgroups. RESULTS: Initial severity according to Pirani (p = 0.020) and Dimeglio score (p = 0.006), number of casts (p = 0.000) and tenotomy (p = 0.045) were significantly higher in bilateral than in unilateral cases. In bilateral cases, a significant correlation was found between the right and left foot of each patient in terms of initial severity, number of casts and tenotomy performed. No statistically significant difference was found according to sex and family history. CONCLUSIONS: This study has confirmed the different behaviour of bilateral cases reported by previous studies; bilateral cases are more severe and show similar features in their right and left foot. This could be the result of different pathogenic mechanisms, likely on a genetic basis. Sex and family history did not seem to influence severity. LEVEL OF EVIDENCE: Level of evidence II.

Extraskeletal Chondroma: A Rare Cause of Trigger Finger in Children.

INTRODUCTION: Trigger finger is ten times less common than trigger thumb in infants and children and, unlike trigger thumb, may arise from a variety of underlying causes. To our knowledge, we describe the first case of pediatric trigger finger secondary to an extraskeletal chondroma. CASE PRESENTATION: We report the case of an 11-year-old girl presenting with a typical history of triggering of the fourth finger, in whom a nodule attached to the flexor digitorum superficialis was found; clinical, ultrasound, and operative findings are described. Histological analysis was diagnostic of extraskeletal chondroma, also known as chondroma of soft tissues. CONCLUSION: This is a very uncommon benign cartilaginous tumor, mostly reported in patients aged 30 to 60 years (just one pediatric extraskeletal chondroma of the hand has been described), and presentation with trigger finger has been reported just once, in a 76-year-old man. This condition should be considered in the differential diagnosis of pediatric trigger finger.

Well-defined Ir/Pd complexes with a triazolyl-diylidene bridge as catalysts for multiple tandem reactions.

The ligand 1,2,4-trimethyl-triazolyl-diylidene has been used for the preparation of a series of three iridium/palladium heterometallic complexes that have been fully characterized. The presence of the two different metals allows tandem processes to be designed by combining reactions that are typically catalyzed by Ir and Pd. Three tandem reactions have been studied: dehalogenation/transfer hydrogenation of haloacetophenones, Suzuki-coupling/transfer hydrogenation of p-bromoacetophenone, and Suzuki-coupling/alpha-alkylation of p-bromoacetophenone. All three reactions yielded excellent outcomes to the corresponding final products, with the relevant feature that the heterodimetallic complexes are more active than the sum of the corresponding homodimetallic species. All three catalytic reactions reported here constitute unprecedented examples of tandem approaches to complex organic molecules.

Total knee replacement in acute and chronic traumatic events.

Total knee replacement (TKR) is a widely used procedure for the treatment of post-traumatic arthritis. This type of solution has also been used recently for the treatment of acute fractures around the knee, particularly in joints that were already arthritic before the trauma. The purpose of this paper is to present our experience with TKR in both acute and chronic traumatic events, highlighting the main problems associated with these conditions and focussing on the indications, principles of technique, tips, tricks and pitfalls of this procedure. The main issues related to post-traumatic arthritis and the problem of TKR in acute fractures are discussed, and our case series of both groups of patients is presented.