3692-69-1Relevant academic research and scientific papers
A concept for stimulated proton transfer in 1-(phenyldiazenyl)naphthalen-2-ols
Hristova,Deneva,Pittelkow,Crochet,Kamounah,Fromm,Hansen,Antonov
, p. 91 - 99 (2018)
A series of aryl azo derivatives of naphthols (1–3) were studied by means of UV–Vis and NMR spectroscopy in different solvents as well as by quantum chemical calculations and X-ray analysis. Previous studies have shown that Sudan I (1) exists as a tautomeric mixture. The effect of the solvents is minimized by the existing intramolecular hydrogen bond. Therefore, the influence on the tautomeric state in structurally modified 1 has been investigated. Structure 2 contains an additional OH-group, which deprotonates easily and affects the position of the tautomeric equilibrium by changing the electronic properties of the substituent. The implementation of a sidearm in 3 creates a condition for competition between the nitrogen from the azo group and from the piperidine unit for the tautomeric proton. In this case the use of acid as a stimulus for controlling the tautomeric process was achieved.
Enantioselective oxidative biaryl coupling reactions catalyzed by 1,5-diazadecalin metal complexes: Efficient formation of chiral functionalized BINOL derivatives
Li, Xiaolin,Hewgley, J. Brian,Mulrooney, Carol A.,Yang, Jaemoon,Kozlowski, Marisa C.
, p. 5500 - 5511 (2007/10/03)
Chiral 1,5-diaza-cis-decalins have been examined as ligands in the enantioselective oxidative biaryl coupling of substituted 2-naphthol derivatives. Under the optimal conditions employing 2.5-10 mol % of a 1,5-diaza-cis-decalin copper(II) catalyst with oxygen as the oxidant, enantioselective couplings (44-96% ee) could be achieved for a range of 3-substituted 2-naphthols including the ester, ketone, phosphonyl, and sulfonyl derivatives. The relationship between the substitution of the naphthalene starting materials and reactivity/selectivity is determined by several factors which act in concert: (1) the effect of substituents on the oxidation potential of the substrate, (2) the ability of the substrate to participate in a chelated copper complex which depends on (a) the inherent coordinating ability of the 3-substituent and (b) substituent steric interactions that affect chelation between the 2-hydroxyl and 3-substituent, (3) the effect of substituents on dissociation of the product from the copper catalyst.
Cation Complexation, Photochromism, and Reversible Ion-Conducting Control of Crowned Spironaphthoxazine
Kimura, Keiichi,Kaneshige, Masayuki,Yamashita, Takashi,Yokoyama, Masaaki
, p. 1251 - 1256 (2007/10/02)
A spironaphthoxazine derivative incorporating a monaza-12-crown-4 moiety at the 5'-position has been designed as a light-resistant, cation-complexable photochromic compound.Complexation of alkali metal ions by the crown moiety in the crowned spironapthoxazine allows the spironaphthoxazine skeleton to isomerize to its corresponding open colored form, even under dark conditions.Specifically, Li(1+) complexation greatly stabilizes the open colored form due to the intramolecular interaction between its oxo group and crown-complexed cation, as well as the selective Li(1+) complexation of its 12-crown-4 moiety.Taking advantage of the high Li(1+) selectivity in the cation-induced isomerization of crowned spironaphthoxazine, the thermal stability of the open colored form can be modulated continuously by added Li(1+) concentrations.Even in the presence of the metal ion, UV- and visible-light irradiation led to futher isomerization to the open form and back-isomerization to the initial closed form, respectively.Photoisomerization of crowned spironaphthoxazine to its open form promoted Li(1+) binding due to the additional axial interaction with the crown-complexed Li(1+), while that back to the closed form attenuated the cation binding.The photoinduced change in the cation-binding ability of crowned spironaphthoxazine, which possesses high light-fatigue resistance, has led to a highly reversible, photochemical switching system of ionic conduction.
