Synthesis of pinacol acetals catalyzed by (2-carboxyphenyl)diphenylphosphonium bromide

<p>(2-Carboxyphenyl)diphenylphosphonium bromide that is readily prepared from commercial 2-(diphenylphosphino)benzoic acid and HBr is an efficient catalyst for the synthesis of pinacol acetals from a variety of aldehydes at room temperature.</p

Synthesis of 1-substituted 2,6,7-trioxa-4-phospha-1-borabicyclo[2.2.2]octan-1-uide

<p>1-Substituted 2,6,7-trioxa-4-phospha-1-borabicyclo[2.2.2]octan-1-uides were obtained in 31–71% yields by the reaction of tetrakis(hydroxymethyl)phosphonium sulfate with alkyl- or arylboronic acids in the presence of tetrabutylammonium hydroxide.</p

In Situ Generation of Formaldehyde and Triphenylphosphine from (Hydroxymethyl)triphenylphosphonium and Its Application in Wittig Olefination

<div><p></p><p>The reaction of (hydroxymethyl)triphenylphosphonium with benzylic or allylic halide under basic conditions at room temperature affords terminal alkenes in 61–89% yields. In this reaction, both formaldehyde and triphenylphosphine are in situ generated from (hydroxymethyl)triphenylphosphonium and further undergo Wittig olefination with benzylic or allylic halide.</p></div

Syntheses of 9-Triptycylisothiocyanate, (10-Amino-9-triptycyl)carboxylic Acid, and Their Derivatives

<div><p></p><p>In the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 9-triptycylisothiocyanate has been synthesized in 91% yield from carbon disulfide and sterically hindered 9-triptycylamine at room temperature. 9-Triptycylisothiocyanate can be further converted to 1-benzyl-3-(9-triptycyl)thiourea. (10-Amino-9-triptycyl)carboxylic acid has also been successfully synthesized via a three-step route starting from methyl 10-nitroanthracene-9-carboylate. Its amino and carboxylic groups can undergo acetylation and amidation, respectively.</p> </div

Cyclic α‑Alkoxyphosphonium Salts from (2-(Diphenylphosphino)phenyl)methanol and Aldehydes and Their Application in Synthesis of Vinyl Ethers and Ketones via Wittig Olefination

Cyclic α-alkoxyphosphonium salts have been synthesized from (2-(diphenyl­phosphino)­phenyl)­methanol and aldehydes in 36–89% yields. These phosphonium salts are bench-stable solids and undergo Wittig olefination with aldehydes under basic conditions (K₂CO₃ or <i>t</i>-BuOK) to form benzylic vinyl ethers, which are readily hydrolyzed to 1,2-disubstituted ethanones under acidic conditions. The formation mechanism of these phosphonium salts via hemiacetal is also proposed

The Microstructural Status of the Corpus Callosum Is Associated with the Degree of Motor Function and Neurological Deficit in Stroke Patients

<div><p>Human neuroimaging studies and animal models have suggested that white matter damage from ischemic stroke leads to the functional and structural reorganization of perilesional and remote brain regions. However, the quantitative relationship between the transcallosal tract integrity and clinical motor performance score after stroke remains unexplored. The current study employed a tract-based spatial statistics (TBSS) analysis on diffusion tensor imaging (DTI) to investigate the relationship between white matter diffusivity changes and the clinical scores in stroke patients. Probabilistic fiber tracking was also used to identify structural connectivity patterns in the patients. Thirteen ischemic stroke patients and fifteen healthy control subjects participated in this study. TBSS analyses showed that the corpus callosum (CC) and bilateral corticospinal tracts (CST) in the stroke patients exhibited significantly decreased fractional anisotropy and increased axial and radial diffusivity compared with those of the controls. Correlation analyses revealed that the motor and neurological deficit scores in the stroke patients were associated with the value of diffusivity indices in the CC. Compared with the healthy control group, probabilistic fiber tracking analyses revealed that significant changes in the inter-hemispheric fiber connections between the left and right motor cortex in the stroke patients were primarily located in the genu and body of the CC, left anterior thalamic radiation and inferior fronto-occipital fasciculus, bilateral CST, anterior/superior corona radiate, cingulum and superior longitudinal fasciculus, strongly suggesting that ischemic induces inter-hemispheric network disturbances and disrupts the white matter fibers connecting motor regions. In conclusion, the results of the present study show that DTI-derived measures in the CC can be used to predict the severity of motor skill and neurological deficit in stroke patients. Changes in structural connectivity pattern tracking between the left and right motor areas, particularly in the body of the CC, might reflect functional reorganization and behavioral deficit.</p></div

Wittig Olefination Using Phosphonium Tetraphenylborate in the Absence of Additional Base

<div><p>GRAPHICAL ABSTRACT</p><p></p></div

DTI-TBSS analysis showed significant areas in the stroke compared with those in the controls.

<p>White matter structures showing a significant FA decrease and an AD and RD increase in different brain regions in the stroke group (p_FWE < 0.05 corrected for multiple comparisons). Statistical images were overlapped onto the mean of the skeleton (green) and the MNI152 template (gray-scale) for visualization. L, left; FA, fractional anisotropy; AD, axial diffusivity; RD, radial diffusivity.</p

Scatter plot of correlation analysis.

<p>A significant negative correlation between Fugl-Meyer Motor Assessment (FMA) and China Neurological Deficit Scores (NDS) was observed in stroke patients (r = -0.871, p < 0.001).</p

Statistical comparison of the individual probabilistic maps between groups.

<p>The statistical comparison demonstrated that the tracts connecting left and right motor regions were different between the groups. Compared with the healthy control group, a lower streamline density was detected in the patient group (read to yellow). The observed differences between the two groups were primarily located in the genu and body of the CC, left anterior thalamic radiation and inferior fronto-occipital fasciculus, bilateral CST, anterior/superior corona radiata, cingulum and superior longitudinal fasciculus (SLF). L, left.</p