Anesthetic management of Stanford type B acute aortic dissection that occurred during transcatheter aortic valve implantation under monitored anesthesia care: A case report.

We report a case involving anesthetic management of Stanford type B acute aortic dissection occurred during transcatheter aortic valve implantation (TAVI) under monitored anesthesia care (MAC) in a patient with aortic stenosis (AS). An 87-year-old woman was undergoing TAVI under MAC for severe AS. During the surgery, the patient suddenly moved possibly because of pain. This was followed by hemodynamic collapse. She was then transitioned to general anesthesia, and extracorporeal membrane oxygenation (ECMO) was initiated. Transesophageal echocardiography revealed a Stanford type B acute aortic dissection, which was safely managed perioperatively with appropriate interventions.

A dinuclear Rh(-i)/Rh(i) complex bridged by biphilic phosphinine ligands.

Bimetallic complexes have enabled precise control of catalysis by accumulating two discrete metal centres. In these complexes, bridging ligands are essential to combine multiple metals into one molecule. Among some bridging modes, an unsymmetric bridging mode will differentiate the electronic structures of the two metal centres. In this study, a dinuclear Rh(-i)/Rh(i) complex bridged by tridentate phosphine-phosphinine-phosphine ligands was prepared by reduction of the corresponding Rh(i) complex. Single-crystal X-ray analysis and DFT calculations suggest that the phosphinine ligands adopt an unsymmetric bridging mode wherein phosphinine accepts d-electrons from one Rh centre and, at the same time, donates lone pairs to the other Rh centre.

Atom Swapping on Aromatic Rings: Conversion from Phosphinine Pincer Metal Complexes to Metallabenzenes Triggered by O2 Oxidation.

Herein, we report a novel method for the synthesis of metallabenzenes by swapping the phosphorus atom in an aromatic phosphinine ring with transition metal fragments. The oxidation of a phosphine-phosphinine-phosphine pincer iridium complex by O2 triggered the replacement of the phosphorus atom of the phosphinine ring by an iridium fragment to afford iridabenzene. Dianionic rhodabenzene was also synthesized from a phosphinine rhodium complex by oxidation of the phosphorus atom, followed by subsequent reduction using metallic potassium. The aromaticity of the newly synthesized irida- and rhoda-benzenes was evaluated both experimentally and theoretically.

Reductive Coupling of Carbon Dioxide and an Aldehyde Mediated by a Copper(I) Complex toward the Synthesis of α-Hydroxycarboxylic Acids.

Copper-mediated reductive coupling between CO2 and an aldehyde to form α-hydroxycarboxylic acid was achieved using silylborane as a reductant. CO2 cleanly inserted into a copper-carbon bond that was formed by the reaction between a silylcopper-NHC complex and an aldehyde. A series of reactions that regenerate the silylcopper complex were developed for the synthesis of an α-hydroxycarboxylic acid. After repeating each step iteratively for two cycles, 0.62 equiv of α-hydroxycarboxylic acid based on the copper complex was obtained.

Reversible Polymer-Chain Modification: Ring-Opening and Closing of Polylactone.

A reversible polymer modification involving structural changes of the polymer chains was accomplished for the copolymer of CO2 and butadiene. The bicyclic structures were opened by hydrolysis and aminolysis reactions of the lactone moiety. For the hydrolysis product, the ring-closing of the ring-opened product was achieved by simply heating without any reagents or solvents. Nuclear magnetic resonance and matrix assisted laser desorption/ionization time-of-flight analyses and size-exclusion chromatography measurement of the polymer before ring-opening and after ring-closure suggested the retention of the polymer structure as well as the molecular weight and polydispersity during the reversible processes, proving that the modification can be performed without significant macroscopic changes of the polymer structure.