Syntheses and UV/Vis Properties of Amino‐Functionalized Fulgimides

Abstract

Functionalized fulgimides are regarded as a promising class of photochromic compounds for modulating the structure and function of biomolecules. A new synthetic route to fulgimides bearing amino‐functionalized substituents at the imide nitrogen atom has been developed. The synthesis of the fulgimides has been achieved by base‐catalyzed cyclization of phenacyl esters of the succinamic acids derived from fulgides and N‐Boc‐protected alkyl‐ and aryl‐substituted diamines with triethylamine or tert‐butyllithium. The UV/Vis spectroscopic data and the photochromic properties of these new compounds have been studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Preparation of an Indolylfulgimide‐Adamantane Linker Conjugate with Nitrile Anchoring Groups through Palladium‐Catalyzed Transformations

“…[8,10] However, with these bases the reaction between indole 5 and diethyl isopropylidenesuccinate (6) proceeded sluggishly, and the halfester (Z)-7 was isolated in poor yields. Fortunately, however, with potassium hexamethyldisilazide (KHMDS) in THF the half-ester (Z)-7 was obtained in 36 % isolated yield.…”

“…in benzene at reflux gave fulgimide 2 (Scheme 2) in 67 % yield over the two steps after workup and purification by flash chromatography as a 64:36 mixture of the E and Z isomers. [8] The pure C isomer (C)-2 (Scheme 1) was obtained in 54 % yield by irradiation of a solution of a Z/E isomeric mixture at 365 nm (200 W HBO) in DCM for 12 h and purification by flash chromatography. The C isomer (C)-2, dissolved in DCM, was then irradiated for 4 h with 545 nm light (1000 W, XBO) to yield the pure E isomer (E)-2 (Scheme 1), quantitatively.…”

“…[7] Fulgimides have also been identified as highly thermally and hydrolytically stable photochromic compounds. [8] Furthermore, the imide moiety can be used for the attachment of fluorophores. [9] Fulgimides and their parent fulgides each contain a hexa-1,3,5-triene structural element, and can exist in three isomeric forms: the noncyclizable Z form, the cyclizable E form, and the closed C form, which is obtained upon photochemical 6π-electrocyclization.…”

Azobenzene as Conformational Switch in Model Peptides

“…[25,26] Also, geometric constraints imparted on the azobenzene moiety when incorporated into macrocycles can markedly affect thermal relaxation rates, as well documented with cyclic azobenzene peptides ( Table 2). [23] It should be noted that the [27] and hemithioindigos, [28] which have been developed in the group of Karola Rück-Braun, as well as secondary thioamide bonds, [29][30][31] which would be "minimal invasive" chromophores.…”

Synthesis and spectral-kinetic investigation of fulgimide-based photochromic autocomplexes of the dinitroquinoline series

“…1 In recent years, particular attention has been given to the synthesis and investigation of the properties of thermally irreversible photochromic compounds, in par ticular, of fulgimides, which undergo reversible valence photoisomerization resulting in the transformation of the open form A into the cyclic form B (Scheme 1). [2][3][4] The colorless open form A is transformed into the colored cyclic form B under UV irradiation (hν). The latter form is again transformed into the starting colorless state under visible light irradiation (hν 1 ).…”