50493-10-2Relevant articles and documents
Synthesis of a Three-Bladed Propeller-Shaped Triple [5]Helicene
Saito, Hiromu,Uchida, Akira,Watanabe, Soichiro
, p. 5663 - 5668 (2017)
Three-bladed propeller-shaped triple [5]helicene was synthesized using eliminative and oxidative photocyclization reactions, which proceeded in 37 and 63% yields, respectively. Chromatographic purification gave a mixture of diastereomers, and the PPM and PMM isomers were gradually converted to the thermodynamically more stable PPP and MMM isomers at room temperature. The activation parameters for the racemization of the PPP and MMM isomers were determined, and the structure of the triple [5]helicene was determined by X-ray crystallographic analysis.
Selective fluorescence sensing of Cu(II) and Zn(II) using a simple Schiff base ligand: Naked eye detection and elucidation of photoinduced electron transfer (PET) mechanism
Ganguly, Aniruddha,Ghosh, Soumen,Kar, Samiran,Guchhait, Nikhil
, p. 72 - 80 (2015)
A simple Schiff base compound 2-((cyclohexylmethylimino)-methyl)-naphthalen-1-ol (2CMIMN1O) has been synthesized and characterized by 1H NMR, 13C NMR and FT-IR spectroscopic techniques. A significantly low emission yield of the compound has been rationalized in anticipation with photo-induced electron transfer (PET) from the imine receptor moiety to the naphthalene fluorophore unit. Consequently, an evaluation of the transition metal ion-induced modification of the fluorophore-receptor communication reveals the promising prospect of the title compound to function as a chemosensor for Cu2+ and Zn2+ ions selectively, through remarkable fluorescence enhancement as well as visual changes. While perturbation of the PET process has been argued to be the plausible mechanism behind the fluorescence enhancement, the selectivity for these two metal ions has been interpreted on the grounds of an appreciably strong binding interaction. Particularly notable aspects regarding the chemosensory activity of the compound is its ability to detect the aforesaid transition metal ions down to the level of micromolar concentration (detection limit being 2.74 and 2.27 ppm respectively), along with a simple and efficient synthetic procedure.
Electrophilic Aromatic Formylation with Difluoro(phenylsulfanyl) methane
Betterley, Nolan M.,Kongsriprapan, Sopanat,Chaturonrutsamee, Suppisak,Deelertpaiboon, Pramchai,Surawatanawong, Panida,Pohmakotr, Manat,Soorukram, Darunee,Reutrakul, Vichai,Kuhakarn, Chutima
, p. 2033 - 2040 (2018/03/21)
Difluoro(phenylsulfanyl)methane (PhSCF 2 H) was found to undergo a reaction with aromatic compounds mediated by SnCl 4, through a thionium intermediate characterized by NMR and TD-DFT analyses, leading to the formation of a mixture of S, S ′-diphenyl dithioacetal and aromatic aldehyde which, after oxidative hydrolysis, provides the aromatic aldehyde in good to excellent yields. The salient feature of the present work is the reaction of activated aromatic compounds containing a deactivating ester functional group, leading to the formylated products in good yields.
Remarkable Ability of the Benzylidene Ligand To Control Initiation of Hoveyda–Grubbs Metathesis Catalysts
Basak, Tymoteusz,Grudzień, Krzysztof,Barbasiewicz, Micha?
supporting information, p. 3513 - 3523 (2016/07/29)
The structure of the chelating benzylidene ligand offers the unique ability to control the initiation of Hoveyda–Grubbs metathesis catalysts. Apart from steric and electronic effects acting on the step involving opening of the chelate ring, changes related to the following ligand-exchange process may also play a critical role. Our mechanistic model reveals that ligands substituted at the 6-position of the benzylidene ring enter the metathesis cycle in a nonoptimal chelating conformation, and thus the coordination number of the ruthenium center transiently increases to six (associative mechanism). In effect, the synthesis and initiation of the catalysts becomes difficult, and the energy barrier of the ligand-exchange process is controlled by the structure of the coordinating OR group. Moreover, we explain how isomeric naphthalene ligands affect the catalytic performance by an indivisible combination of steric and π-electron delocalization effects.
