A theoretical study on the elimination reaction of acrylonitrile from 2′-O-cyanoethylated nucleosides by Bu4NF

The elimination reaction of acrylonitrile from 2′-O-cyanoethylated nucleosides by Bu₄NF was studied computationally. The transition structures for the reaction of 3-methoxypropionitrile with Me₄NF were located at the MP2, B3LYP, and B3LYP-SCRF(Dipole) levels with 6-31 + G* basis set. The α-hydrogen of the cyano group was removed via a proton transfer from the α-carbon to the oxygen with a syn-periplanar arrangement rather than the deprotonation reaction with F^?. In the presence of an excess amount of Me₄NF, the activation energy decreased by the coordination of Me₄N⁺ to the cyano group. The reaction of 3-methoxypropionitrile with Bu₄NF and 2′-O-cyanoethylated uridine with Me₄NF also occurred via a proton transfer mechanism with lower activation energies. The reactivity tendency corresponds to the amount of the negative charge on the oxygen atom and part of the reason for the faster elimination with F^? rather than with DBU concerns entropy. The experimental results are well explained by these calculations.     

Acceleration effects of 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene with 2‐methylimidazole‐intercalated α‐zirconium phosphate as a latent thermal initiator in the reaction of glycidyl phenyl ether and hexahydro‐4‐methylphthalic anhydride

The catalytic effects of 1,5,7‐Triazabicyclo[4.4.0]dec‐5‐ene (TBD) with 2‐methylimidazole‐intercalated α‐zirconium phosphate (α‐ZrP?2MIm) in the reaction of glycidyl phenyl ether (GPE) and hexahydro‐4‐methylphthalic anhydride (MHHPA) were investigated. The reaction did not proceed within 1 h at 60 °C. On increasing the temperature to 100 °C, the conversion reached 93% for 1 h. Without the addition of TBD, the conversion was 67% at 100 °C for 1 h. Under storage conditions at 25 °C for 7 days, the conversion of GPE was only 18%. The curing behavior of 2,2‐bis(4‐glycidyloxyphenyl)propane (DGEBA) and MHHPA in the presence of TBD with α‐ZrP?2MIm was evaluated by differential scanning calorimetry. The addition of TBD with α‐ZrP?2MIm as a latent thermal initiator, the storage stability was maintained and the reaction proceeded rapidly under heating conditions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2557–2561     

Tribo-Excited Chemical Reaction Using an EuIII Complex with a Stacked Anthracene Framework

A spin-selective tribo-chemical reaction using a dinuclear lanthanide complex is demonstrated for the first time. The dinuclear complex is composed of two Eu^III ions, hexafluoroacetylacetonato ligands, and anthracene-based phosphine oxide bridges. Single-crystal analysis revealed a face-to-face-type anthracene dimer structure in the dinuclear Eu^III complex. Mechanical stimulus on the dinuclear Eu^III complex induced selective formation of oxidized anthracene. The tribo-chemical reaction is based on a characteristic energy-transfer pathway for the selective formation of an excited triplet state.     

Bis(2-t-butylphenyl)phosphonoacetamides for the highly cis-selective synthesis of α,β-unsaturated amides

New Horner–Wadsworth–Emmons reagents, (o-t-BuPhO)₂P(O)CH₂CONMe(OMe) and (o-t-BuPhO)₂P(O)CH₂CON(CH₂CH₂) ₂O were prepared via the Arbuzov reaction in good yields. The HWE reaction of these reagents with a variety of aldehydes gave cis-α,β-unsaturated amides with high selectivity in almost quantitative yields.     

Conformational Change of Spermidine upon Interaction with Adenosine Triphosphate in Aqueous Solution

A complex rotation : The solution conformation of spermidine (SPD) was elucidated by using diastereospecifically deuterated and ¹³C‐labeled derivatives to diagnose the orientation of seven conformationally relevant bonds. NMR coupling constants were determined for a complex formed from spermidine and adenosine triphosphate (ATP; see figure).

     

Inflammation-induced synergetic enhancement of nanoparticle treatments with DOXIL<Superscript>®</Superscript> and <Superscript>90</Superscript>Y-Lactosome for orthotopic mammary tumor

Polymeric micelles (Lactosome) in the size of 20–30 nm were labeled with radionuclides of ¹¹¹In (¹¹¹In-DOTA-Lactosome) for SPECT imaging and ⁹⁰Y (⁹⁰Y-DOTA-Lactosome) for β-ray irradiation for mammary tumor in mice. The tumor site at the femoral right leg grafted with 4T1 cells was clearly imaged at 24 h after the intravenous injection. Biodistribution revealed that the half-life time of ¹¹¹In-DOTA-Lactosome was 11 h, which enabled the nanoparticle selectively accumulated in tumor site due to the enhanced permeability and retention (EPR) effect. The anti-tumor therapeutic effect of ⁹⁰Y-DOTA-Lactosome was observed depending on the dose frequency and amount. Under the condition of the percutaneous ethanol injection treatment, the therapeutic effect of ⁹⁰Y-DOTA-Lactosome was enhanced due to the super EPR effect. Owing to the super EPR effect, co-administration of ⁹⁰Y-DOTA-Lactosome and DOXIL^® inhibited the tumor growth during 15 days with their administrations.