TY - JOUR

T1 - P2O5-Promoted Cyclization of Di[aryl(hetaryl)methyl] Malonic Acids as a Pathway to Fused Spiro[4.4]nonane-1,6-Diones

AU - Ivanov, Konstantin S.

AU - Riesebeck, Tim

AU - Skolyapova, Alexandrina

AU - Liakisheva, Irina

AU - Kazantsev, Maxim S.

AU - Sonina, Alina A.

AU - Peshkov, Roman Yu

AU - Mostovich, Evgeny A.

N1 - Funding Information: This work was supported by Ministry of Science and Higher Education of Russian Federation project No FSUS-2020-0036 and later FSUS-2021-0014. Resource center “VTAN” (Novosibirsk State University) is acknowledged for the access to experimental equipment and Multi-Access Chemical Research Center SB RAS for spectral and analytical measurements. Publisher Copyright: © 2022 American Chemical Society.

PY - 2022/3/4

Y1 - 2022/3/4

N2 - Conventional spiro-linked conjugated materials are attractive for organic optoelectronic applications due to the unique combination of their optical and electronic properties. However, spiro-linked conjugated materials with conjugation extension directed along the main axis of the molecule are still only rare examples among the vast number of spiro-linked conjugated materials. Herein, the synthesis, leading to π-extended spiro-linked conjugated materials-spiro[4.4]nonane-1,6-diones and spiro[5.5]undecane-1,7-diones-has been developed and optimized. The proposed design concept starts from readily available malonic esters and contains several steps: double alkylation of malonic ester with bromomethylaryl(hetaryl)s; conversion of a malonic ester into the corresponding malonic acid; electrophilic spirocyclization of the latter into the annulated spiro[4.4]nonane-1,6-dione or spiro[5.5]undecane-1,7-dione in the presence of phosphorus pentoxide. On the basis of these insights, the developed method yielded spiro-linked conjugated cores fused with benzene, thiophene, and naphthalene, decorated with active halogen atoms. The structures of the synthesized spirocycles were determined by single-crystal X-ray diffraction analysis. Benzene fused spiro[4.4]nonane-1,6-dione decorated with bromine atoms was transformed into V-shape phenylene-thiophene co-oligomer type spirodimers via Stille coupling. The spiro-bis(4-n-dodecylphenyl)-2,2′-bithiophene derivative possessed high photoluminescence properties in both solution and solid state with a photoluminescence quantum yield (PL QY) of 38%.

AB - Conventional spiro-linked conjugated materials are attractive for organic optoelectronic applications due to the unique combination of their optical and electronic properties. However, spiro-linked conjugated materials with conjugation extension directed along the main axis of the molecule are still only rare examples among the vast number of spiro-linked conjugated materials. Herein, the synthesis, leading to π-extended spiro-linked conjugated materials-spiro[4.4]nonane-1,6-diones and spiro[5.5]undecane-1,7-diones-has been developed and optimized. The proposed design concept starts from readily available malonic esters and contains several steps: double alkylation of malonic ester with bromomethylaryl(hetaryl)s; conversion of a malonic ester into the corresponding malonic acid; electrophilic spirocyclization of the latter into the annulated spiro[4.4]nonane-1,6-dione or spiro[5.5]undecane-1,7-dione in the presence of phosphorus pentoxide. On the basis of these insights, the developed method yielded spiro-linked conjugated cores fused with benzene, thiophene, and naphthalene, decorated with active halogen atoms. The structures of the synthesized spirocycles were determined by single-crystal X-ray diffraction analysis. Benzene fused spiro[4.4]nonane-1,6-dione decorated with bromine atoms was transformed into V-shape phenylene-thiophene co-oligomer type spirodimers via Stille coupling. The spiro-bis(4-n-dodecylphenyl)-2,2′-bithiophene derivative possessed high photoluminescence properties in both solution and solid state with a photoluminescence quantum yield (PL QY) of 38%.

UR - http://www.scopus.com/inward/record.url?scp=85125128997&partnerID=8YFLogxK

U2 - 10.1021/acs.joc.1c02379

DO - 10.1021/acs.joc.1c02379

M3 - Article

C2 - 35166542

AN - SCOPUS:85125128997

VL - 87

SP - 2456

EP - 2469

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 5

ER -