4-Dimethylaminoacetophenone O-vinyloxime: Synthesis and steric structure
摘要:
4-Dimethylaminoacetophenone oxime was synthesized from 4-dimethylaminoacetophenone and hydroxylamine hydrochloride. Its reaction with acetylene in the system KOH-DMSO gave previously unknown 4-dimethylaminoacetophenone O-vinyloxime as the major product. According to the experimental data and quantum-chemical calculations, 4-dimethylaminoacetophenone O-vinyloxime is formed as the only E isomer with preferential s-trans conformation of the vinyloxy group, which is characterized by essentially nonplanar structure.
Isomer-Specific Hydrogen Bonding as a Design Principle for Bidirectionally Quantitative and Redshifted Hemithioindigo Photoswitches
作者:Joshua E. Zweig、Timothy R. Newhouse
DOI:10.1021/jacs.7b04448
日期:2017.8.16
quantitative bidirectional isomerization. Additionally, extending conjugation from the electron-rich pyrrole results in quantitative visible-light photoswitches, as well as photoswitches that isomerize with red and near-infrared light. The presence of the hydrogen bond leading to the observed redshift is supported by computational and spectroscopicevidence.
In this work, a novel synthetic methodology for the preparation of aryl pyrroles directlyfrom the reaction of calcium carbide with oxime is reported. Various pyrrole derivatives are generated from the corresponding oximes in satisfactory yields (49–88%) under the optimized conditions. The one-pot synthesis of aryl pyrrole from widely available ketone is also successfully developed. A new near-infrared
Palladium-Catalyzed Cross-Coupling of Pyrrole Anions with Aryl Chlorides, Bromides, and Iodides
作者:Ryan D. Rieth、Neal P. Mankad、Elisa Calimano、Joseph P. Sadighi
DOI:10.1021/ol048367m
日期:2004.10.1
enyl ligands, (pyrrolyl)zinc chloride may be cross-coupled with a wide range of aryl halides, including aryl chlorides and arylbromides, at low catalyst loadings and under mild conditions. A high degree of steric hindrance is tolerated. Certain ring-substituted pyrrole anions have also been arylated with arylbromide substrates.
Non-symmetric benzo[b]-fused BODIPYs as a versatile fluorophore platform reaching the NIR: a systematic study of the underlying structure–property relationship
作者:André Bessette、Thomas Auvray、Denis Désilets、Garry S. Hanan
DOI:10.1039/c5dt04444h
日期:——
BODIPYs are compared with an extended series of nine related families (23 compounds) to gain insights into their structure–property relationship. The insertion of a fused indole moiety into the dipyrromethene core and various substituents on the proximal aryl including fused aromatic groups, lead to pronounced changes in the properties of compounds 1–10. By taking advantage of this versatile synthetic
4'-diaminodiphenyls (via an intermediate cyclohexadienyl cation) or is reduced to the aniline (via the aniline radicalcation) in a ratio depending on the hydrogen-donating properties of the solvent. Transients attributable to the triplet aminophenyl cation as well as to the ensuing intermediates are detected. Chemical evidence for the generation of the phenyl cation is given by trapping via electrophilic substitution