Synthesis, Structures, and Photophysical Properties of Optically Stable 1,16-Diphenyl-3,14-diaryl-Substituted Tetrahydrobenzohelicenediol Derivatives: Enantioselective Recognition toward Tryptophan Methyl Esters
Starting from commercially available 7-methoxytetralone, 1,16-diphenyl-3,14-dibromotetrahydrobenzohelicenediol (Br-HHOL) was conveniently prepared, which underwent efficient resolution to give the optically stable enantiomeric diols in gram scale by HPLC with semipreparative chiral columns. The absolute configurations of the diols were determined by the circular dichroism (CD) spectra and X-ray crystal structure. By Suzuki–Miyaura cross-coupling reactions, a series of enantiopure π-extended 1,16-diphenyl-3,14-diaryltetrahydrobenzohelicenediol derivatives (Ar-HHOL) were further synthesized in high yields. The enantiomeric Ar-HHOL exhibited almost identical absorption and emission spectra but showed mirror-image CD spectra and mirror-image circularly polarized luminescence properties. Moreover, it was also found that aryl substituents at the 3,14-positions could extend the chiral environment of the helical skeletons, which led to efficient enantioselective recognition of the enantiomers of tr...
Lei Fang; Meng Li; Wei-Bin Lin; Yun Shen; Chuan-Feng Chen
We recently generalized the formerly alignment-dependent multivariate image analysis applied to quantitative structure–activity relationships (MIA-QSAR) method through the application of the discrete Fourier transform (DFT), allowing for its application to noncongruent and structurally dive ... more
Poly-ADP-ribosylation (PARylation) is a protein posttranslational modification (PTM) that is critically involved in many biological processes that are linked to cell stress responses. It is catalyzed by a class of enzymes known as poly-ADP-ribose polymerases (PARPs). In particular, PARP1 is ... more
This review focuses on the type A cytochrome c oxidases (CcO), which are found in all mitochondria and also in several aerobic bacteria. CcO catalyzes the respiratory reduction of dioxygen (O2) to water by an intriguing mechanism, the details of which are fairly well understood today as a r ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more