Abstractα‐ and β‐Cyclodextrins have been used as scaffolds for the synthesis of six‐ and seven‐legged templates by functionalizing every primary CH2OH with a 4‐pyridyl moiety. Although these templates are flexible, they are very effective for directing the synthesis of macrocyclic porphyrin oligomers consisting of six or seven porphyrin units. The transfer of chirality from the cyclodextrin templates to their nanoring hosts is evident from NMR and circular dichroism spectroscopy. Surprisingly, the mean effective molarity for binding the flexible α‐cyclodextrin‐based template within the six‐porphyrin nanoring (74 M) is almost as high as for the previously studied rigid hexadentate template (180 M). The discovery that flexible templates are effective in this system, and the availability of a template with a prime number of binding sites, open up many possibilities for the template‐directed synthesis of larger macrocycles.
A Complex Comprising a Cyanine Dye Rotaxane and a Porphyrin Nanoring as a Model Light‐Harvesting System
作者:Jiratheep Pruchyathamkorn、William J. Kendrick、Andrew T. Frawley、Andrea Mattioni、Felipe Caycedo‐Soler、Susana F. Huelga、Martin B. Plenio、Harry L. Anderson
DOI:10.1002/anie.202006644
日期:2020.9.14
A nanoring‐rotaxane supramolecularassembly with a Cy7 cyaninedye (hexamethylindotricarbocyanine) threaded along the axis of the nanoring was synthesized as a model for the energy transfer between the light‐harvesting complex LH1 and the reaction center in purple bacteria photosynthesis. The complex displays efficient energy transfer from the central cyaninedye to the surrounding zinc porphyrin nanoring
Synthesis, Structure−Activity Relationships, and Pharmacological Profile of 9-Amino-4-oxo-1-phenyl-3,4,6,7-tetrahydro[1,4]diazepino[6,7,1-<i>h</i><i>i</i>]indoles: Discovery of Potent, Selective Phosphodiesterase Type 4 Inhibitors
The synthesis, structure-activity relationships, and biological properties of a novel series of; potent and selective phosphodiesterase type 4 (PDE4) inhibitors are described. These new aminodiazepinoindoles displayed in vitro PDE4 activity with submicromolar IC50 values and PDE4 selectivity vs PDE1, -3, and -5. Specifically, one compound (CI-1044, 10e) provided efficient in vitro inhibition of TNF alpha release from hPBMC and; hWB with IC50:values of 0.34 and 0.84 muM, respectively. This compound was found to exhibit potent in vivo activity in antigen-induced eosinophil recruitment in Brown-Norway rats (ED50 = 3.2 mg/kg po) and in production of TNF alpha in Wistar fats (ED50 = 2.8; mg/kg po). No emetic side effects at therapeutic doses were observed in ferrets.
Convenient syntheses of 1,1,1,3,3,3-hexafluoro-2-organyl-propan-2-ols and the corresponding trimethylsilyl ethers
A new convenient synthetic procedure to obtain various 1, 1, 1,3,3,3-hexafluoro-2-organyl-propan-2-ols and the corresponding trimethylsilyl ethers has been worked out starting from anhydrides or activated esters of carboxylic acids and trimethyl(trifluoromethyl)silane in the presence of tetramethylammonium fluoride. Conditions for the selective formation of 1, 1, 1,3,3,3-hexafluoro-2-organyl-propan-2-ols as well as the trimethylsilyl derivatives have been found. (C) 2004 Elsevier Ltd. All rights reserved.