2158-31-8Relevant articles and documents
Asymmetric meso-CF3-BODIPY dyes based on cycloalkanopyrroles
Hu, Rui,Petrushenko, Konstantin B.,Sagitova, Elena F.,Sobenina, Lyubov N.,Tomilin, Denis N.,Trofimov, Boris A.,Ushakov, Igor A.,Yang, Guoqiang
, (2020)
New meso-CF3-substituted BODIPY derivatives have been synthesized using the methodology that includes as a key step the condensation of pyrroles with trifluoro(2,3-cycloalkanopyrrol-2-yl)ethanols. The further reaction of dipyrromethanes thus obtained with DDQ followed by complexation with BF3 leads to either benzo[b]-fused (in the case of dipyrromethanes obtained from trifluoro(4,5,6,7-tetrahydroindol-2-yl)ethanol) or cycloheptano[b]-fused saturated or partially saturated BODIPY dyes. The latter exhibit strong red fluorescence (λem = 588–634 nm, Φf = 0.54–0.68), while benzo[b]-fused do not fluoresce at all in either polar or non-polar solvents. The performed quantum-chemical calculations (TD-CAM-B3LYP/SVP) explain the spectroscopic results.
Arylboronic Acid-Catalyzed C-Allylation of Unprotected Oximes: Total Synthesis of N-Me-Euphococcine
Kürti, László,Kattamuri, Padmanabha V.,Siitonen, Juha H.,Yousufuddin, Muhammed
supporting information, (2020/03/24)
O-Unprotected keto-and aldoximes are readily C-allylated with allyl diisopropyl boronate in the presence of arylboronic acid catalysts to yield highly substituted N-α-secondary and tertiary homoallylic hydroxylamines. The method was used in the total synthesis of the trace alkaloid N-Me-Euphococcine.
Copper-Catalyzed Radical C-C Bond Cleavage and [4+1] Annulation Cascade of Cycloketone Oxime Esters with Enaminothiones
He, Yuan,Lou, Jiang,Wu, Kaikai,Wang, Hongmei,Yu, Zhengkun
supporting information, (2019/02/14)
Carbon-carbon bond formation is among the most important reactions in organic synthesis. Reconstruction of a carbon-carbon bond through ring-opening C-C bond cleavage of a strained carbocycle usually occurs via a thermodynamically preferable pathway. However, carbon-carbon bond formation through thermodynamically less favorable C-C bond cleavage has seldom been documented. Herein, we disclose an unusual C-C bond cleavage of cycloketone oxime esters for [4+1] annulation. Under anaerobic copper(I) catalysis, cycloketone oxime esters underwent regioselective, thermodynamically less favorable radical C-C bond cleavage followed by annulation with enaminothiones; that is, α-thioxo ketene N,S-acetals efficiently affording 2-cyanoalkyl-aminothiophene derivatives. Cyclobutanone, -pentanone, -hexanone, and -heptanone oxime esters could act as the effective C1 building blocks in the annulation reaction. An iminyl radical mechanism is proposed for the rare C-C bond cleavage/[4+1] annulation cascade.