Regioselective One-Pot Synthesis of Vicinal Bisphosphine Derivatives from Nitroalkenes by Hydrophosphinylation/Elimination/Hydrophosphinylation.

Herein, a facile method is developed for the synthesis of vicinal bisphosphine derivatives based on a cascade of hydrophosphinylation, elimination, and hydrophosphinylation of secondary phosphine oxides with nitroalkenes. This cascade reaction provides step-economy access to a series of vicinal bisphosphine derivatives with high to excellent yields (up to 99%). This method was further extended to prepare, in one-pot, regioselective vicinal bisphosphine derivatives that incorporated two different phosphorus functional groups.

The conformational behavior of N‑ethylformamide as observed by rotational spectroscopy and quantum chemistry.

A peptide linkage (CO)NH containing molecule, N-ethylformamide, was investigated by rotational spectroscopy in order to determine the molecular constants of its highest-energy conformer, cis-ac. Its rotational spectrum was observed in two different frequency ranges, in the 4-26 GHz frequency region using a Fourier transform microwave spectrometer and at millimeter wave frequencies between 75 and 116 GHz, employing a broadband high-resolution rotational spectrometer. The measurements at low frequencies allowed to resolve the hyperfine structure components due to nitrogen nuclear quadrupole coupling while the data at higher frequencies provided spectroscopic information about high order centrifugal effects.

Synthesis of Chiral α-Substituted β-Aminophosphine Derivatives through Asymmetric Hydrophosphinylation Utilizing Secondary Phosphine Sulfides.

The organocatalytic enantioselective hydrophosphinylation of various secondary phosphine sulfides with aromatic and aliphatic nitroalkenes is presented in this study. The reaction produced chiral β-nitrophosphine sulfides with excellent yields and enantioselectivities (up to 99% yield and 99% ee). Furthermore, the chiral β-nitrophosphine sulfides can be easily converted into α-substituted β-aminophosphine, which is a family of useful P, N-ligands and phosphine catalysts.

Conformations and Low-Frequency Intramolecular Motions of 1-Butanol, 1-Butanethiol, -butanol, and -butanethiol Investigated by Fourier Transform Microwave Spectroscopy Combined with Quantum Chemical Calculations.

The rotational spectra of 1-butanol (1-BuOH), 1-butanethiol (1-BuSH), 2-methyl-1-propanol (-BuOH), and 2-methyl-1-propanethiol (-BuSH) were measured by Fourier transform microwave spectroscopy in the frequency region from 3.7 up to 25 GHz. The observed spectral lines were assigned by observation of the deuterium substitution effect and by ab initio or density functional theory calculations at the levels of MP2/6-311++G(d,p) or B3LYP and -B3LYP, respectively.

Factors related to the satisfaction level of elderly hearing-impaired individuals with cochlear implants.

Objective: This study investigated factors related to the satisfaction level of cochlear implants for the elderly.

Methods: A survey was conducted by sending an anonymous self-reported questionnaire to medical facilities specializing in cochlear implantation throughout Japan and members of cochlear implant self-help groups aged 65 years and older. The subjects were divided into two age-based groups (under 75 and 75 years and older) to analyze the usage of cochlear implants.