Ein Spiroindolinopyran mit schaltbarer optischer Aktivität

Eggers, Lutz; Buß, Volker

doi:10.1002/ange.19971090816

Cited by 8 publications

(3 citation statements)

References 11 publications

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“…Although several solvent and crystallization conditions were explored no crystals could be obtained from the separated C3′ enantiomers of compound 8 , which were accessible after enantiomeric enrichment of compound 4 by chiral liquid chromatography on tris(3,5‐dimethylphenylcarbamoyl)cellulose/SiO 2 . This unusual behavior for spiropyrans was observed previously and seems to be a consequence of the additional stereogenic spiro center of compound 8 31. Therefore, synthesis was continued with a mixture of enantiomers of compound 8 .…”

Section: Resultssupporting

confidence: 67%

Spiropyran Photoswitches in the Context of DNA: Synthesis and Photochromic Properties

Brieke

Heckel

2013

Chemistry A European J

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A new design is presented for the incorporation of spiropyran photoswitches into nucleic acids by oligonucleotide solid phase synthesis. This design enables interaction of the 6-nitrospirobenzopyran (NitroBIPS) photoswitch with the adjacent nucleobases and leaves the photochemical properties of NitroBIPS intact. UV/Vis spectroscopy and HPLC revealed that NitroBIPS incorporated into DNA consists of up to 40 % merocyanine in its thermal equilibrium and undergoes reversible switching between the photoisomeric spiropyran (SP) and merocyanin (MC) state by alternating excitation using visible light or heat for at least fifteen switching cycles. Exchanging the chromene part of NitroBIPS on the DNA level gives access to differently substituted spiropyran derivatives allowing the screening for spiropyrans with suitable properties in a straightforward manner. Thus, by incorporating the highly hydrolysis-stable pyrido-spiropyran derivative PyBIPS pure light-triggered reversible switching of a spiropyran in DNA has been realized for the first time. Therefore, this design represents a new useful platform for investigating the photochromic behavior of different spiropyran photoswitches in a nucleic acid environment and for using spiropyrans to induce light- or heat-triggered changes in conformations or in fluorescence quenching properties of oligonucleotides.

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Section: Resultssupporting

confidence: 67%

Spiropyran Photoswitches in the Context of DNA: Synthesis and Photochromic Properties

Brieke

Heckel

2013

Chemistry A European J

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“…Reading the change in chiral information originated in photochromic reactions is one of the most promising systems, since chiral information can be read without excitation of photochromic compounds 4, 5. In photocyclization systems, for example, diarylethenes,5a fulgides,5b and spiropyrans,5c the enantiomers of the photochromic compounds undergo diastereoselective photocyclization. In these systems, one should be aware of the diastereoselectivity of the cyclization, since such selectivity is altered by the conditions (e.g.…”

Section: Methodsmentioning

confidence: 99%

Enantioselective Photochromic Reaction of a [2.2]Metacyclophan-1-ene We are grateful for financial support from The Association for the Progress of New Chemistry (ASPRONC).

Takeshita

Yamato

2002

Angew. Chem.

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Photochromic compounds have been extensively studied owing to their potential as photomemory and photoswitching materials. [1] Photochromic compounds reversibly change their absorption spectra (color) upon photoirradiation. However, reading the photomemory by changes in the absorption spectrum causes the destruction of the memory, since photoirradiation results in excitation of photochromic compounds. [1] Therefore, various attempts at nondestructive readout have been reported, [1] for example, by locking one of the photoisomers by the addition of chemical substances [2] or by electrooxidation (gated photochromic reaction). [3] Reading the change in chiral information originated in photochromic reactions is one of the most promising systems, since chiral information can be read without excitation of photochromic compounds. [4,5] In photocyclization systems, for example, diarylethenes, [5a] fulgides, [5b] and spiropyrans, [5c] the enantiomers of the photochromic compounds undergo diastereoselective photocyclization. In these systems, one should be aware of the diastereoselectivity of the cyclization, since such selectivity is altered by the conditions (e.g. temperature, medium, etc). This fact encouraged us to study enantiomeric photocyclization, that is, a photochromic reaction between two enantiomers in which no racemization takes place.We chose 1,2-disubstituted [2.2]metacyclophan-1-enes (MCP-1-enes), [6] which we recently reported, [7] as the enantiomeric photocyclization system (Scheme 1). It is well known that ring inversion of the phenyl groups in the anti 8,16dimethyl[2.2]metacyclophane system is forbidden because of the steric hindrance between the inner methyl groups and the opposite phenyl groups. [8] For similar reasons, ring inversion of MCP-1-enes does not occur, and MCP-1-enes are chiral molecules because no mirror symmetry exists in the molecule. UV UV Vis Vis tBu Me Me tBu N O O p-tolyl Me Me tBu tBu N O O p-tolyl tBu Me Me tBu N O O p-tolyl Me Me tBu tBu N O O p-tolyl 1a 1b enantiomers enantiomers Scheme 1. Enantioselective photochromic reaction of [2.2]MCP-1-ene 1 a and THP 1 b.Therefore, one can expect that racemization of the enantiomers of MCP-1-enes does not take place. MCP-1-enes show photochromism, [6,7] and tetrahydropyrenes (THP) formed from MCP-1-enes by UV irradiation are also chiral. It is expected that no racemization occurs, even during the photochromic reaction, and that the photochromic reaction takes place with both enantiomers. We have designed and synthesized some MCP-1-enes and found that the enantiomers of maleimide-type MCP-1-ene 1 a are easily separated. [9] MCP-1-ene 1 a was synthesized from 1,2-dicyano[2.2]MCP-1-ene [7] in three steps. [10] Figure 1 shows Figure 1. Changes in the absorption spectrum of 1 a (0.16 mm in hexane) upon irradiation with 313-nm light. Numbers indicate the irradiation time (s).the changes in the absorption spectrum of a solution of 1 a in hexane upon irradiation with 313-nm light. The pale yellow solution of 1 a changed to violet upon UV irrad...

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“…If this is achieved, it may be possible to steer or even switch chirality, e.g. depending on temperature or light …”

mentioning

confidence: 99%

Enantiomeric Resolution of Cycloenantiomeric Rotaxane, Topologically Chiral Catenane, and Pretzel-Shaped Molecules: Observation of Pronounced Circular Dichroism

et al. 1997

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Ein Spiroindolinopyran mit schaltbarer optischer Aktivität

Cited by 8 publications

References 11 publications

Spiropyran Photoswitches in the Context of DNA: Synthesis and Photochromic Properties

Spiropyran Photoswitches in the Context of DNA: Synthesis and Photochromic Properties

Enantioselective Photochromic Reaction of a [2.2]Metacyclophan-1-ene We are grateful for financial support from The Association for the Progress of New Chemistry (ASPRONC).

Enantiomeric Resolution of Cycloenantiomeric Rotaxane, Topologically Chiral Catenane, and Pretzel-Shaped Molecules: Observation of Pronounced Circular Dichroism

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