Rhodium-Catalyzed Synthesis of 2-Methylindoles via C-N Bond Cleavage of N-Allylbenzimidazole.

A rhodium-catalyzed oxidative C-H/N-H dehydrogenative [3 + 2] annulation strategy has been reported between anilines and N-allylbenzimidazole for the synthesis of 2-methylindole scaffolds. An N-allylbenzimidazole has been used as a 2C synthon for the synthesis of indole, and more importantly, this transformation involves the cleavage of the thermodynamically stable C-N bond of allylamine. Detailed mechanistic studies have been performed and a key intermediate was detected in HRMS. This transformation proceeds through a cascade of C(sp2)-H allylation followed by intramolecular cyclization.

Annulation of Indole-2-Carboxamides with Bicycloalkenes Catalyzed by Ru(II) at Room Temperature: An Easy Access to ß-Carboline-1-one Derivatives under Mild Conditions.

Herein, we report the annulation of indole-2-carboxamides with bicycloalkenes, to synthesize ß-carboline-1-one derivatives under mild conditions. The commercially available ruthenium catalyst was used for the reaction. This reaction tolerates a wide range of functional groups and affords a good yield of ß-carboline-1-one derivatives. A reversible cyclometalation pathway was found to be operative in the mechanistic study.

Pyridone Directed Ru-Catalyzed Olefination of sp2(C-H) Bond Using Michael Acceptors: Creation of Drug Analogues.

Herein, the ruthenium-catalyzed regioselective sp2(C-H) monoalkenylation of N-arylpyridones has been demonstrated, where the pyridone was utilized as a weakly coordinating directing group. Importantly, the current methodology has been effectively applied to the synthesis of many drug analogues such as pirfenidone, naproxen, ibuprofen, geraniol, umbelliferone, pregnenolone, and estrone. This methodology tolerates a wide range of functional groups and yields up to 93% yield. A six-membered ruthenium complex was also detected by HRMS.

Cobalt(III)-Catalyzed C-6 Alkenylation of 2-Pyridones by Using Terminal Alkyne with High Regioselectivity.

Co(III)-catalyzed alkenylation of 2-pyridones by using terminal alkyne as a reaction partner with high regioselectivity has been demonstrated for the first time. The reaction conditions are mild and compatible with a wide range of substrate combinations. It also shows good functional group tolerance. It proceeds through cyclometalation followed by alkyne insertion and protodemetalation steps. The formation of five- and seven-membered cobaltacycle intermediates was also detected through high-resolution mass spectrometry.

Ruthenium-Catalyzed Cross Dehydrogenative Annulation of N-(7-Azaindole)benzamides with Maleimides: One-Step Access to Highly Functionalized Pyrroloisoquinoline.

A ruthenium(II)-catalyzed cross dehydrogenative annulation of N-(7-azaindole)benzamides with maleimides has been demonstrated. Herein, we have explored the use of N-amino-7-azaindole as a new bidentate directing group for dehydrogenative [4 + 2] annulation. This method works efficiently, affording a variety of pharmacologically useful 7-azaindole-based isoquinolones and showing a wide functional group tolerance.

Rhodium-Catalyzed One-Pot Access to N-Polycyclic Aromatic Hydrocarbons from Aryl Ketones through Triple C-H Bond Activations.

A Rh-catalyzed pot and step economic synthesis of aza-polycyclic aromatic hydrocarbons (N-PAHs) from readily available aryl ketones and alkynes has been disclosed. Additionally, a novel synthetic application of the well-known aminating reagent hydroxylamine-O-sulfonic acid (HOSA) has been explored as an in situ redox-neutral directing group for the formation of N-PAHs via isoquinoline. Multiple bond formation in a single operation through a cascade of triple C-H bond activations is the beauty of this protocol. The challenging annulations of two different alkynes in a regioselective fashion have been demonstrated effectively. Mechanistic studies reveal that 3,4-diphenyl-1-methylisoquinoline is an active intermediate for this one-pot transformation.

Redox-Neutral Cobalt(III)-Catalyzed C-H Activation/Annulation of α,ß-Unsaturated Oxime Ether with Alkyne: One-Step Access to Multisubstituted Pyridine.

A redox neutral Co(III)-catalyzed annulation of α,ß-unsaturated oxime ether with alkyne has been reported. Multisubstituted pyridines were synthesized in good yields without the use of any heavy metal oxidants. The developed methodology tolerates a variety of functional groups. Notably, this transformation has been applied to the late-stage modification of the bioactive molecule dehydropregnenolone.

Use of extracorporeal membrane oxygenation and cerebral oximetry in a stage 1 norwood repair for hypoplastic left heart syndrome.

The role of extracorporeal membrane oxygenation (ECMO) and its indications in stage I Norwood palliation are controversial. The decision to initiate ECMO and its timing remains difficult with no definitive cut-off points or evidence-based guidelines. It varies on a case-to-case basis. We report a case where the use of ECMO was beneficial after stage I Norwood palliation with severe ventricular dysfunction. The systemic-to-pulmonary artery shunt was kept open to balance the systemic and pulmonary circulations. Cerebral oximetry can be useful as an additional monitoring modality to guide management, monitor cerebral perfusion, and help detect cerebral steal.

Overcoming the Challenges toward Selective C(6)-H Functionalization of 2-Pyridone with Maleimide through Mn(I)-Catalyst: Easy Access to All-Carbon Quaternary Center.

An earth-abundant and inexpensive Mn(I)-catalyzed alkylation of 2-pyridone with maleimide has been reported for the first time, in contrast to previously reported Diels-Alder products. Notably, an unexpected rearrangement has been discovered in the presence of acetic acid, which also provides a unique class of compounds bearing three different N-heterocycles with an all-carbon quaternary center. Furthermore, single crystal X-ray and HRMS revealed a five-membered manganacycle intermediate. This methodology tolerates a wide variety of functional groups delivering the alkylated products in moderate to excellent yields.

Switching the Reactivity of the Nickel-Catalyzed Reaction of 2-Pyridones with Alkynes: Easy Access to Polyaryl/Polyalkyl Quinolinones.

A Ni-catalyzed C6 followed by C5 cascade C-H activation/[2 + 2 + 2] annulation of 2-pyridone with alkynes has been achieved. A change in the reaction pathway was achieved by tuning the reaction conditions and incorporating a directing group. A wide variety of substrates and alkynes are amenable to this transformation. The key to success for this transformation is the use of sodium iodide as an additive. More importantly, we detected the five-membered metallacycle intermediate through HRMS wherein iodide is ligated to the metal.

N-Allylbenzimidazole as a strategic surrogate in Rh-catalyzed stereoselective trans-propenylation of aryl C(sp2)-H bond.

A Rh-catalyzed C(sp2)-H propenylation has been reported by taking N-allyl benzimidazole as an allylamine congener. This transformation has been observed for the first time, where a tandem process of C-H allylation followed by alkene isomerization delivers a highly stereoselective trans-propenylated product. Detailed mechanistic studies including the characterization of rhodacycle-intermediates have been conducted to understand the mechanism.

Correction to: A shining star of congenital heart surgery-a tribute to Dr. William I Norwood Jr (1941-2020).

[This corrects the article DOI: 10.1007/s12055-021-01161-w.].

Synthesis and Photophysical Study of Heteropolycyclic and Carbazole Motif: Nickel-Catalyzed Chelate-Assisted Cascade C-H Activations/Annulations.

Herein, nickel-catalyzed synthesis of polyarylcarbazole through sequential C-H bond activations has been described. Regioselective indole C2/C3 functionalization has been achieved in the presence of indole C7-H, which is quite challenging. In addition, this approach also gives easy access to building a heteropolycyclic motif through C6/C7 C-H functionalization of indoline. This methodology is not limited to aromatic internal alkynes as coupling partners; aliphatic alkynes have also shown good tolerance. Notably, during the optimization the catalytic enhancement with sodium iodide as an additive has been observed. We have also studied the photophysical properties of these highly conjugated molecules.

Hypoplastic left heart syndrome: current modalities of treatment and outcomes.

Hypoplastic left heart syndrome is a constellation of malformations which result from the severe underdevelopment of any left-sided cardiac structures. Once considered to be universally fatal, the prognosis for this condition has tremendously improved over the past four decades since the work of William Norwood in the early 1980s. Today, a staged surgical approach is applied for palliating this distinctive cohort of patients, in which they undergo three operative procedures in the first 10 years of their life. Advancements in medical technologies, surgical techniques, and our growing experience in the management of HLHS have made survival into adulthood a possibility. Through this review, we present the different phases of the staged approach with primary focus on stage 1-its modifications, current technique, alternatives, and latest outcomes.

Coronary transfer in the arterial switch operation: the modified closed technique.

Arterial switch operation for transposition of great arteries (TGA) is the choice of surgical treatment for this condition. Conventional "open" coronary transfer technique has been commonly employed with good results in experienced hands. A modified "closed" technique of coronary transfer, with a more accurate coronary artery placement taking into account a distended aorta, along with anterior interrupted sutures to reduce purse stringing and other advantages is described.

Potts shunt as an effective palliation for patients with end stage pulmonary arterial hypertension.

BACKGROUND: Potts shunt has been suggested as an effective palliative therapy for patients with pulmonary artery hypertension (PAH) not associated with congenital heart disease. MATERIALS AND METHODS: This is a prospective single-center study performed to assess outcomes of Potts shunt in patients with PAH who are in functional class III or IV. RESULTS: 52 patients in functional class III/IV with pulmonary arterial hypertension without significant intra or extracardiac shunt on maximal medical therapy were evaluated and counseled for undergoing Potts shunt/patent ductus arteriosus (PDA) stenting. 16/52 patients (13 females) consented for the procedure; 14 patients underwent surgical creation of Potts, and 2 underwent transcatheter stenting of PDA, which physiologically acted like a Potts shunt. Standard medical therapy was continued in patients who did not consent for the procedure. 12/16 patients survived the procedure. Patients who did not survive the procedure were older, with severe right ventricular systolic dysfunction, and functional class IV. Patients who survived the procedure were followed up in the pulmonary hypertension clinic. The Median follow-up was 17 months (1-40 months). 11/13 patients discharged after the operation showed sustained clinical, echocardiographic, and biochemical improvement, which reduced need for pulmonary vasodilator therapy in 10/13 patients. There was one death in the follow-up period 16 months post-surgery due to lower respiratory tract infection. CONCLUSION: Potts shunt is feasible in patients with PAH without significant intra or extracardiac shunts. It can be done safely with an acceptable success rate. Patient selection, preoperative stabilization, and meticulous postoperative management are essential. It should be performed at the earliest sign of clinical, echocardiographic, or laboratory deterioation for optimal outcomes. Long-term follow-up is required to see a sustained improvement in functional class and the need for a lung transplant in the future.

Manipulating Edge Current in Hexagonal Boron Nitride via Doping and Friction.

We map spatially correlated electrical current on the stacking boundaries of pristine and doped hexagonal boron nitride (hBN) to distinguish from its insulating bulk via conductive atomic force microscopy (CAFM). While the pristine edges of hBN show an insulating nature, the O-doped edges reveal a current 2 orders of higher even for bulk layers where the direct transmission through tunnel barrier is implausible. Instead, the nonlinear current-voltage characteristics (I-V) at the edges of O-doped hBN can be explained by trap-assisted lowering of the tunnel barrier by adopting a Poole-Frenkel (PF) model. However, in the stacked heterostructure with multilayer graphene (MLG) on top, the buried edge of pristine hBN shows a signature of electron conduction in the scanning mode which contradicts the first-principle calculation of spatial distribution of local density of states (LDOS) data. Enhancement of friction between the Pt-tip and MLG at the step-edge of the heterostructure while scanning in the contact mode has prompted us to construct a phenomenological model where the localization of opposite surface charges on two conducting plates (MLG and Si substrate) containing a dielectric film (hBN) with negatively charged defects creates an internal electric field opposite to the external electric field due to the applied voltage bias in the CAFM setup. An equivalent circuit with a parallel resistor network based on a vertical conducting channel through the MLG/hBN edge and an in-plane surface carrier transport through MLG can successfully analyze the current maps on pristine/doped hBN and the related heterostructures. These results yield fundamental insight into the emerging field of insulatronics in which defect-induced electron transport along the edge can be manipulated in an 1D-2D synergized insulator.

Single-Stage Repair of Interrupted Aortic Arch With Aortopulmonary Window and Bovine-Type Aortic Arch Complicated by Left Subclavian Artery Origin Stenosis-A Case Report.

An aortopulmonary window is known to be associated in 5% of interrupted aortic arch cases. The combination of these lesions with a bovine-type aortic arch is much more uncommon. We report its embryological explanation and successful single-stage surgical repair in a three-month-old infant.

A case of esophagogastroduodenoscopy induced Takotsubo cardiomyopathy with complete heart block.

Takotsubo cardiomyopathy (TC) describes a reversible left ventricular dysfunction characterized by apical ballooning and basal hyperkinesis, commonly triggered by emotional or physical distress. TC associated with an esophagogastroduodenoscopy (EGD) has rarely been reported. We report a case of TC with complete heart block (CHB) in a patient receiving an EGD, who had no underlying cardiac disease, had previously tolerated both local and general anesthesia, and who had previously undergone similar endoscopic procedures without complications. The concurrence of both TC and CHB is unique in this case pertaining to a patient with no significant risk factors. The incidence, mechanism and prognosis of TC-associated arrhythmias are also reviewed.

Elective delayed sternal closure portends better outcomes in congenital heart surgery: a retrospective observational study.

INTRODUCTION: Delayed sternal closure is used in paediatric cardiac surgery as a management strategy for patients with unstable hemodynamics or postoperative bleeding routinely. We hypothesise that planned postponement of sternal closure leads to better outcomes than emergent reopening in the intensive care unit (ICU) in patients exhibiting some hemodynamic indication for the same. METHODS: We retrospectively analysed the outcomes of delayed sternal closure 220/2111 (10.42%) out of which 14 sternums were opened in the ICU after shifting the patients. RESULTS: A total of 220/2111 (10.42%) sternums were left open postoperatively, out of which 14 were opened after shifting to the ICU. Total mortality of the delayed sternal closure was 33/220, i.e. 15%. The patients whose sternums were left open from the theatre had a mortality of 23/206, i.e. 11.16%, whereas those patients whose sternums were opened in the ICU had a mortality of 10/14, i.e. 71.42%. CONCLUSION: In doubtful postoperatively hemodynamic, the choice of leaving the sternum open electively has better outcomes, rather than opening the sternum as a terminal bail out procedure.