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A facile benzylic alkylation of indenes and other arenes was developed from readily available primary and secondary alcohols using our newly investigated CCC pincer IrIII catalyst (SNIr−H). Excellent regioselectivity and yield (89 %) of the C3‐alkylated indenes were obtained. Additionally, the challenging sp2C‐alkylation was readily accomplished. This method could be utilized for the synthesis of the analogs of a histamine H1 receptor antagonist and the functional material template molecule, indeno[2,1‐a]indene. A hemilabile IrIII‐dihydride intermediate was proposed based on control experiments and previous density functional theory (DFT) calculations for the borrowing hydrogen mechanism and is key to the success of this IrIII catalyst in the reduction of unactivated multi‐substituted olefin intermediates. [ABSTRACT FROM AUTHOR]

Monoalkylation of aniline can be readily achieved using trichloroacetimidate as an alkylating agent and a Brønsted acid, such as (±)-camphorsulfonic acid, as a catalyst. In this study, systematic theoretical calculations were performed to understand the reaction mechanism for the monoalkylation of 2,5-dichloroaniline with trichloroacetimidate catalyzed by (±)-camphorsulfonic acid; moreover, the judgement about whether the reaction takes place via an SN1 or SN2 mechanism was elaborated. The two possible proton-transfer reaction mechanisms proposed herein based on the experimental results were investigated; moreover, another two possible reaction mechanisms involving the activation of both 2,5-dichloroaniline and trichloroacetimidate by (±)-camphorsulfonic acid via dual hydrogen-bonding activation modes were evaluated. The calculated results suggest that the reaction between 2,5-dichloroaniline and trichloroacetimidate catalyzed by (±)-camphorsulfonic acid preferentially occurs through the SN1 mechanism based on the dual hydrogen-bonding activation modes. [ABSTRACT FROM AUTHOR]

Triethylene diamine (DABCO) has the characteristic of being hydrophilic and exhibits a color change in air because its N atom can interact with H2O and CO2. To understand these phenomena, herein, theoretical calculations on the intermolecular interactions between DABCO and H2O (or CO2) were carried out at the M06-2X/aug-cc-pVDZ level without and with the counterpoise method, and single-point calculations at the CCSD(T)/aug-cc-pVDZ level were also performed. The electron donating ability of DABCO was revealed by the molecular surface electrostatic potential and Fukui function. The driving forces for the formation of a dimer and trimer were uncovered by EDA analyses. Because DABCO can interact with both H2O and CO2, the formation of hydrogen bonds and tetrel bonds is competitive, and meanwhile, DABCO can interact with H2O and CO2 simultaneously, so the hydrogen bond and tetrel bond can coexist and cooperate with each other. The hydrogen bond and tetrel bond in the dimers and trimers were proven and analyzed by NCI and QTAIM. The results presented here will provide useful insight in understanding the hydrophilic characteristic and the color change of DABCO. [ABSTRACT FROM AUTHOR]

Mexiletine and lidocaine are widely used class IB anti-arrhythmic drugs that are considered to act by blocking voltage-gated open sodium currents for treatment of ventricular arrhythmias and relief of pain. To gain mechanistic insights into action of anti-arrhythmics, we characterized biophysical properties of Nav1.5 and Nav1.7 channels stably expressed in HEK293 cells and compared their use-dependent block in response to mexiletine and lidocaine using whole-cell patch clamp recordings. While the voltage-dependent activation of Nav1.5 or Nav1.7 was not affected by mexiletine and lidocaine, the steady-state fast and slow inactivation of Nav1.5 and Nav1.7 were significantly shifted to hyperpolarized direction by either mexiletine or lidocaine in dose-dependent manner. Both mexiletine and lidocaine enhanced the slow component of closed-state inactivation, with mexiletine exerting stronger inhibition on either Nav1.5 or Nav1.7. The recovery from inactivation of Nav1.5 or Nav1.7 was significantly prolonged by mexiletine compared to lidocaine. Furthermore, mexiletine displayed a pronounced and prominent use-dependent inhibition of Nav1.5 than lidocaine, but not Nav1.7 channels. Taken together, our findings demonstrate differential responses to blockade by mexiletine and lidocaine that preferentially affect the gating of Nav1.5, as compared to Nav1.7; and mexiletine exhibits stronger use-dependent block of Nav1.5. The differential gating properties of Nav1.5 and Nav1.7 in response to mexiletine and lidocaine may help explain the drug effectiveness and advance in new designs of safe and specific sodium channel blockers for treatment of cardiac arrhythmia or pain. [ABSTRACT FROM AUTHOR]

Crinipellins are a significant class of naturally occurring highly congested tetraquinane diterpenoids, with many members exhibiting bio-important antibacterial and anticancer activities. However, their complex structures, particularly their dense 5/5/5/5 tetracyclic frameworks, have made efficient synthesis challenging, leading chemists to attempt to create highly efficient and divergent routes. This study presents a concise, divergent synthesis of six crinipellins, completed in just 9-11 steps using commercially available materials. Particular highlights include: (1) a vital one-step 4π-electrocyclization/dicycloexpansion cascade that rapidly constructs the angular/fused tetraquinane scaffold with two contiguous quaternary carbons, and (2) strategic functionalizations through iso-propylation, methylation, and Wacker oxidation/dehydrogenation, enabling the divergent syntheses of the six crinipellin members without using protecting groups. This approach provides a versatile platform for accessing additional crinipellin derivatives, which we believe will benefit medicinal and biological research., (© 2025 Wiley-VCH GmbH.)

An unusual cascade C-H activation, vinylation and 6π-electrocyclization of 2-pyridyl aldimines with vinyl bromides/triflates was achieved using catalysis with a unique CCC pincer NHC-Ru(iii) complex (Cat B). This reaction was found to enable a rapid and diverse synthesis of polycyclic 4 H -pyrido[1,2- a ]pyrimidine derivatives in mostly good to high yields, and with a broad substrate scope. A mechanistic study suggested the formation of a semi-opened Ru(iii) intermediate chelating/activating the aldimine, and the occurrence of single-electron transfer (SET) to generate a vinyl radical, followed by vinylation and then an intramolecular 6π-electrocyclization of 1 N ,3 N -hexatrene to form the product. This protocol provides a convenient approach for preparing and seeking new drug candidates., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

BACKGROUND Cardiac calcified amorphous tumor (CCAT), a peculiar and uncommon non-neoplastic cardiac lesion, was initially characterized by Reynolds and colleagues in the medical literature in 1997. This distinctive entity is hallmarked by its unique feature of pedunculated and diffused calcifications, primarily infiltrating the cardiac structures, with a predilection for the mitral valve annulus initially, followed in sequence by the right atrium, right ventricle, left atrium, left ventricle, and tricuspid valve annulus. The nature of CCATs, despite being benign, poses diagnostic dilemmas, as they frequently masquerade as malignant tumors due to their clinical presentations, which resemble those caused by potential complications such as obstructive masses and thromboembolic events. CASE REPORT A 50-year-old man presented to our hospital with shortness of breath. He had been short of breath for more than 5 years after repeated activities. Transthoracic echocardiography showed a mobile high echogenic mass from the middle of the right ventricular wall and pericardial effusion and right heart insufficiency. The electrocardiogram (ECG) results demonstrated a sinus rhythm, complete right bundle branch block, and T-wave alterations. Additionally, the chest computed tomography (CT) scan revealed a slightly enlarged heart with a lack of density and calcification in the right ventricle. He had an uneventful postoperative recovery after the resection of the cardiac tumor. The mass had not continued to grow when we compared it with preoperative cardiac color doppler echocardiography, after 3 months follow-up. CONCLUSIONS CCAT is a rare non-neoplastic cardiac entity. Diagnosis of CCAT poses a challenge due to the absence of distinct clinical features and its frequent misidentification as a malignant tumor mimic. Surgical resection serves as the sole treatment for symptom relief.

A catalytic enantioselective polycyclization of tertiary enamides with terminal silyl enol ethers has been developed by virtue of Cu(OTf) 2 catalysis with a novel spiropyrroline-derived oxazole (SPDO) ligand. This tandem reaction offers an effective approach to assemble bicyclic and tricyclic N -heterocycles bearing both aza - and oxa -quaternary stereogenic centers, which are primal subunits in a range of natural alkaloids. Strategic application of this methodology and a late-stage radical cyclization as key steps have been showcased in the concise total synthesis of (-)-cephalocyclidin A.