Enantioselective reductive multicomponent coupling reactions between isatins and aldehydes

A reductive coupling of two different carbonyls via a polar two-electron reaction mechanism was developed and the stereochemical outcome of this multicomponent process is precisely controlled by a chiral triaminoiminophosphorane

JASMINE: Near-infrared astrometry and time-series photometry science

The Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is Galactic archaeology with a Galactic Center survey, which aims to reveal the Milky Way’s central core structure and formation history from Gaia-level (∼25 ${\mu}$as) astrometry in the near-infrared (NIR) Hw band (1.0–1.6 ${\mu}$m). The other is an exoplanet survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic Center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information on the stars in the Galactic Center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic Center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars, and microlensing studies, including discovery of (intermediate-mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions

o-Quinone methide with overcrowded olefin component as a dehydridation catalyst under aerobic photoirradiation conditions

An o-quinone methide (o-QM) featuring an overcrowded olefinic framework is introduced, which exhibits dehydridation activity owing to its enhanced zwitterionic character, particularly through photoexcitation. The characteristics of this o-QM enable the operation of dehydridative catalysis in the oxidation of benzylic secondary alcohols under aerobic photoirradiation conditions. An experimental analysis and density functional theory calculations provide mechanistic insights; the ground-state zwitterionic intermediate abstracts a hydride and proton simultaneously, and the active oxygen species facilitate catalyst regeneration

Chiral ammonium betaine-catalyzed asymmetric Mannich-type reaction of oxindoles

A highly diastereo- and enantioselective Mannich-type reaction of 3-aryloxindoles with N-Boc aldimines was achieved under the catalysis of axially chiral ammonium betaines. This catalytic method provides a new tool for the construction of consecutive quaternary and tertiary stereogenic carbon centers on biologically intriguing molecular frameworks with high fidelity

Correction to “Generation of Chiral Phosphonium Dialkyl Phosphite as a Highly Reactive <i>P</i>‑Nucleophile: Application to Asymmetric Hydrophosphonylation of Aldehydes”

Correction to “Generation of Chiral Phosphonium Dialkyl Phosphite as a Highly Reactive <i>P</i>‑Nucleophile: Application to Asymmetric Hydrophosphonylation of Aldehydes

Acridinium Betaine as a Single-Electron-Transfer Catalyst: Design and Application to Dimerization of Oxindoles

An intramolecular ion-pairing acridinium phenoxide possessing a redox-active component and a basic site within a single molecular framework is developed. The potential of the acridinium betaine as a chemical redox catalyst is demonstrated by its application to the homodimerization of 3-aryl oxindoles, which proceeds through proton-coupled electron-transfer pathway. Analysis of the kinetic profile has provided important clues to understand the reaction mechanism