Catalytic Deoxygenative Coupling of Aromatic Esters with Organophosphorus Compounds
作者:Miki B. Kurosawa、Ryota Isshiki、Kei Muto、Junichiro Yamaguchi
DOI:10.1021/jacs.0c02839
日期:2020.4.22
We have developed a deoxygenative coupling of aromatic esters with diarylphosphine oxides/dialkyl phosphonates under palladium ca-talysis. In this reaction, aromatic esters can work as novel benzylation reagents to give the corresponding benzylic phosphorus compounds. The key of this reaction is the use of phenyl esters, an electron-rich diphosphine as a ligand, and sodium formate as a hydrogen source
我们开发了在钯催化下芳族酯与二芳基膦氧化物/二烷基膦酸酯的脱氧偶联。在该反应中,芳族酯可作为新型苄基化试剂生成相应的苄基磷化合物。该反应的关键是使用苯酯、富电子二膦作为配体,以及甲酸钠作为氢源。芳基羧酸也适用于该反应,使用 (Boc)2O 作为添加剂。钯/dcype 用于激活酯的酰基 CO 键并支持甲酸钠的还原。
pK<sub>a</sub> tuning in quadrupolar-type two-photon ratiometric fluorescent membrane probes
Two ratiometric two-photon pH probes were designed, combining pKa values close to physiological pH and large two-photon absorption responses. They are able to stain efficiently GUV and cell membranes.
The synthesis of polyenes with 3 or 5 conjugated double bonds bearing alkylanthryl and alkylpyridinium terminal groups is described. Alkyl chains of suitable length were introduced in both the anthracene and/or pyridine moiety to reduce the solubility in water thus improving the ability to form Langmuir-Blodgett films.
Herstellung konjugierter Polyene mit Anthryl- und<i>N</i>-Methylpyridinium- Endgruppen
作者:Franz Effenberger、Claus-Peter Niesert
DOI:10.1055/s-1992-26322
日期:——
Preparation of Conjugated Polyenes with Anthryl and N-Methylpyridinium Terminal Groups The synthesis of terminally donor-acceptor substituted polyenes from the respective aldehydes via Horner reactions is described. As donor group the 9-anthryl and as acceptor moiety the 4-(N-methyl)pyridinium residue were chosen. A bicyclo[2.2.2]octane unit was incorporated into the chain to interrupt the conjugation. The separation and characterization of the mixtures of Z/E- isomers obtained in the syntheses was possible.
Amphiphilic cationic polyenic pushâpull chromophores
which offer interesting supramolecular possibilities for second harmonic
generation have been synthesised and their optical non-linearities studied
for the first time by electric field induced second harmonic (EFISH)
generation in solution.