4222-20-2Relevant articles and documents
One-pot synthesis of photochromic naphthopyrans in the solid state
Tanaka, Koichi,Aoki, Hiroko,Hosomi, Hiroyuki,Ohba, Shigeru
, p. 2133 - 2134 (2000)
matrix presented p-TsOH-catalyzed condensation reactions of 1,1-diaryl-2-propyn-1-ol (1) and 2-naphthol (2) in the solid state gave 3,3-diaryl-3H-naphtho[2,1-b]pyran (6) via Claisen rearrangement. Similar reactions of 1 with 2,6-(7) and 2,7-dihydroxynaphthalenes (8) afforded naphthodipyrane derivatives 9 and 10, respectively. Bis-naphthopyran derivatives 12 were also obtained by the reaction of 1,1,6,6-tetraaryl-2,5-hexadiyn-1,6-diol (11) and 2-naphthol (2) in the solid state.
Photophysics and kinetics of naphthopyran derivatives, part 3: A general procedure to uniquely identify the kinetic and spectroscopic parameters of ABC(2k,2φ) systems and application to naphthopyran reactions
Maafi,Brown
, p. 421 - 430 (2006)
A new procedure has been developed with the aim of determining the kinetic and spectroscopic parameters of any photochemical systems of the generic ABC(2k,1φ) and ABC(2k,2φ) types. General expressions of the colorability and the equilibrium concentration ratio of two (of the three involved) species at a photostationary state or a state of thermal equilibrium have been derived. The procedure has been successfully applied to achieve unique identifiability for the seven sequences of the ABC(2k,1φ and 2φ) type that may represent naphthopyran dynamics. It is demonstrated that the reactivity of this particular compound is certainly described by a higher kinetic level than those (three or four reaction steps) considered in the present study.
Spectral manifestation of protonation of photochromic naphthopyrans
Barachevsky, Valery А.,Gorelik, Alexander М.,Kobeleva, Оlga I.,Valova, Тatyana М.,Venidiktova, Оlga V.
, (2020/09/22)
The formation of proton complexes of the photoinduced colored open form of naphthopyrans in solutions was first discovered and investigated by spectral-kinetic method. The complexes exhibit a new absorption band in the visible region, which is bathochromically shifted relative to the absorption band of the photoinduced colored open form. With an increase in the concentration of perchloric or hydrochloric acid, this long-wavelength absorption band appears immediately after the addition of acids to solutions of photochromic compounds. The protonation efficiency depends on the strength of the acids.
Access to Electron-Deficient 2,2-Disubstituted Chromanes: A Highly Regioselective One-Pot Synthesis via an Inverse-Electron-Demand [4 + 2] Cycloaddition of ortho-Quinone Methides
Tanaka, Kenta,Kishimoto, Mami,Asada, Yosuke,Tanaka, Yuta,Hoshino, Yujiro,Honda, Kiyoshi
, p. 13858 - 13870 (2019/11/03)
We report the one-pot synthesis of 2,2-disubstituted chromanes with electron-withdrawing substituents. This reaction provides a simple yet efficient route to a wide range of electron-deficient chromanes in high yield and excellent regioselectivity. The reaction of salicylaldehyde with 1,1-disubstituted ethylenes smoothly furnishes these electron-deficient chromanes, which can be further transformed into functionalized chromanes or chromene. For example, BW683C was effectively synthesized from 5-chlorosalicylaldehyde with 4-chlorostyrene in two steps in excellent yield. The present reaction thus provides versatile access to functionalized electron-deficient chromanes and chromenes and therefore constitutes a promising tool for the synthesis of biologically and photochemically active molecules.
