Synthesis of hydroquinone-, biphenol-, and binaphthol-containing aza macroheterocycles via regioselective hydroformylation and reductive amination

Rhodium(I) catalyzed regioselective hydroformylation of diolefins and subsequent reductive amination of the dialdehydes in the presence of α,ω-diamines is applied to azamacroheterocyclic ring synthesis Rhodium(I) catalyzed regioselective hydroformylation of diolefins and subsequent reductive amination of the dialdehydes in the presence of α,ω-diamines is applied to azamacroheterocyclic ring synthesis. Starting from aromatic diallyl ethers of hydroquinone, biphenol and binaphthol 20–28 membered macroheterocycles were obtained in up to 78 yield

Fluorescence screening of tartaric acid-derived azamacrocycles synthesized via sequential hydroformylation/reductive amination as potential ligands for asymmetric catalysis

Azamacrocyclic fluorophores containing piperazine units were synthesized using sequential rhodium-catalyzed regioselective hyd Azamacrocycles containing a tartaric acid-derived unit and aryl units were synthesized via rhodium-catalyzed hydroformylation and subsequent reductive amination in a tandem or stepwise fashion. Upon fluorescence emission experiments, some of the macrocycles showed chelating affinities towards transition metals such as zinc or rhodium

A Piperazine-Containing Azamacrocyclic Fluorescent Sensor for Metals

The design and construction of molecular scale sensors are challenging issues in modern nanotechnology. Molecular sensors are sensitive devices which are used for rapid detection of very small amounts of various compounds and metals. The detection of toxic metals such as Hg, Pb, Cd are crucial for environmental protection as well as for medical and pharmaceutical technology.1,2 The design of molecular sensors is based on an interdisciplinary approach, which links different fields of chemical science, from organic to materials chemistry and biochemistry.2 The new fluorophoric ligand 1 was designed in our group as a potential chemosensor for metals. It is synthesized starting from the simple bisallyl olefin of the protected 3,5-dihydroxy-1-benzoic acid and mono-Boc-protected piperazine via sequential regioselective hydroformylation and reductive amination. Recognition of ions Zn2+ and Co2+ by the macrocycle 1 has been detected by fluorescence spectroscopy, and was also confirmed by NMR spectroscopy. The interaction of these metals with the macrocycle is very selective, and can be detected using different wavelengths of excitation. If the complex is excited with a wavelength of 280 nm, fluorescence enhancement is higher in the 1+Zn2+ complex while at an excitation wavelength of 400 nm, fluorescence enhancement for the complex 1+Co2+ was higher.4 These results indicate different stabilities of the electronic states formed by interaction of the metals with macrocycle. The observed selectivity for different metals will result in even more applications of these macrocycles, studies which are currently on going

A Piperazine-Containing Azamacrocyclic Fluorescent Sensor for Metals

The design and construction of molecular scale sensors are challenging issues in modern nanotechnology. Molecular sensors are sensitive devices which are used for rapid detection of very small amounts of various compounds and metals. The detection of toxic metals such as Hg, Pb, Cd are crucial for environmental protection as well as for medical and pharmaceutical technology.1,2 The design of molecular sensors is based on an interdisciplinary approach, which links different fields of chemical science, from organic to materials chemistry and biochemistry.2 The new fluorophoric ligand 1 was designed in our group as a potential chemosensor for metals. It is synthesized starting from the simple bisallyl olefin of the protected 3,5-dihydroxy-1-benzoic acid and mono-Boc-protected piperazine via sequential regioselective hydroformylation and reductive amination. Recognition of ions Zn2+ and Co2+ by the macrocycle 1 has been detected by fluorescence spectroscopy, and was also confirmed by NMR spectroscopy. The interaction of these metals with the macrocycle is very selective, and can be detected using different wavelengths of excitation. If the complex is excited with a wavelength of 280 nm, fluorescence enhancement is higher in the 1+Zn2+ complex while at an excitation wavelength of 400 nm, fluorescence enhancement for the complex 1+Co2+ was higher.4 These results indicate different stabilities of the electronic states formed by interaction of the metals with macrocycle. The observed selectivity for different metals will result in even more applications of these macrocycles, studies which are currently on going

A Rapid and Reliable Assay for Regioselectivity Using Fluorescence Spectroscopy

The first report of a fluorescence-based assay for the direct measurement of the regioselectivity of a reaction is described herein, developed from the desire to construct a quicker analytical method for the determination of the ratio of regioisomers obtained in the tandem hydroformylation/Fischer indole synthesis. The method allows for extremely rapid acquisition times, as the use of crude reaction mixtures is allowed. The assay is also shown to be overall very reliable, tolerating the presence of various functional groups and proceeding on average with a standard error of measurement comparable to that of NMR. As fluorescence is the only requirement for the employment of this analytical method, countless numbers of target-specific assays can undoubtedly be developed based upon this initial finding