Abstract: This study presents a copper-catalyzed, solvent-dependent method for the rapid and efficient synthesis of N-pyrazolo-sulfonamides directly from nitro-pyrazole and sulfonyl hydrazide under microwave conditions. The reaction exhibits notable solvent effects in pyrazole’s reactivity. The ionic liquid DBU-AcOH triggered the reactivity of 4-nitro-pyrazole, whereas the reaction in PEG proceeded selectively at the 3- & 5-positions of pyrazole. Key applications of this method include the gram-scale synthesis of pyrazolo-sulfonamide, sulfaphenazole analogue and sulfonamide
{"title":"Copper-Catalyzed Chemoselective Synthesis of Pyrazolo-Sulfonamide: Impact of Solvent on Nitro-pyrazole Reactivity","authors":"Subhendu Bhowmik, RANA SAHA, Swarnendu Dutta, Arka Das, Rajarshi Jana, Krutika Sonar, Sreya Gupta","doi":"10.1002/ejoc.202401097","DOIUrl":"https://doi.org/10.1002/ejoc.202401097","url":null,"abstract":"Abstract: This study presents a copper-catalyzed, solvent-dependent method for the rapid and efficient synthesis of N-pyrazolo-sulfonamides directly from nitro-pyrazole and sulfonyl hydrazide under microwave conditions. The reaction exhibits notable solvent effects in pyrazole’s reactivity. The ionic liquid DBU-AcOH triggered the reactivity of 4-nitro-pyrazole, whereas the reaction in PEG proceeded selectively at the 3- & 5-positions of pyrazole. Key applications of this method include the gram-scale synthesis of pyrazolo-sulfonamide, sulfaphenazole analogue and sulfonamide","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A twisted chiral nanographene (NG) surrounded by eight bulky tert-butyl groups fused with emissive chromophore perylene was synthesized by highly regioselective cyclodehydrogenation strategy in which a double [6]helicene was formed simultaneously. The twisted 4-meso was unambiguously confirmed by single crystal X-ray analysis. The NG showed an excellent photoluminescence quantum yield (φf) of 55%, indicating its great potential for chiral optoelectronics.
通过高区域选择性环化氢化策略合成了一种由八个笨重的叔丁基环绕的扭曲手性纳米石墨烯（NG），并与发射性发色团苝融合，同时形成了双 [6] 螺旋烯。通过单晶 X 射线分析，明确地确认了扭曲的 4-meso。该 NG 的光致发光量子产率 (φf) 高达 55%，显示了其在手性光电子学方面的巨大潜力。
{"title":"Perylene Based Twisted Emissive Curved Nanographene Synthesis through Scholl Reaction","authors":"Siddhartha Samanta, Sahina Khatun, Sanhita Maity, Anirban Pradhan","doi":"10.1002/ejoc.202401170","DOIUrl":"https://doi.org/10.1002/ejoc.202401170","url":null,"abstract":"A twisted chiral nanographene (NG) surrounded by eight bulky tert-butyl groups fused with emissive chromophore perylene was synthesized by highly regioselective cyclodehydrogenation strategy in which a double [6]helicene was formed simultaneously. The twisted 4-meso was unambiguously confirmed by single crystal X-ray analysis. The NG showed an excellent photoluminescence quantum yield (φf) of 55%, indicating its great potential for chiral optoelectronics.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new environmentally friendly and efficient strategy for preparing trifluoromethylated pyrrolidones has been developed. The process involves using visible light to induce radical cyclization of 1,5-dienes with CF3SO2Na, resulting in excellent regioselectivity. This method uses less expensive and easy-to-store trifluoromethylation reagents, making it an attractive option. Additionally, the resulting trifluoromethylated pyrrolidones can be easily modified and preliminary mechanistic studies have been presented.
{"title":"Photocatalytic Regioselective Tandem Cyclization Protocol to Trifluoromethylated Pyrrolidones","authors":"Panpan Wang, Yuting Leng, Kaixia Sui, Shiliang Jiang, Ning Ma, Yangjie Wu","doi":"10.1002/ejoc.202401023","DOIUrl":"https://doi.org/10.1002/ejoc.202401023","url":null,"abstract":"A new environmentally friendly and efficient strategy for preparing trifluoromethylated pyrrolidones has been developed. The process involves using visible light to induce radical cyclization of 1,5-dienes with CF3SO2Na, resulting in excellent regioselectivity. This method uses less expensive and easy-to-store trifluoromethylation reagents, making it an attractive option. Additionally, the resulting trifluoromethylated pyrrolidones can be easily modified and preliminary mechanistic studies have been presented.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chalcogen bond catalysis is a promising catalytic strategy, characterized by its environmental friendliness, relatively inexpensive cost, and similar reactivity to transition metal catalysis. Experimental results suggest that the S•••π and Se•••π bonds can efficiently drive the vinyl-indole-based Diels-Alder reaction (Angew. Chem. Int. Ed. 2021, 60, 9395-9400). In this work, chalcogen bond catalysis in the Diels-Alder reaction between 2-vinylindoles has been investigated based on density functional theory. For this reaction, the Te•••π bond catalysis is as an alternative catalytic strategy. The Diels-Alder reaction catalyzed by chalcogen bond is stepwise and involves two steps: the carbon–carbon bond formation process and the cyclization process. The cyclization process is the rate-determining step. From the perspective of energy decomposition analysis, the electrostatic interaction is the main factor to cause Se•••π bond catalysis, the polarization interaction is the main factor to cause Te•••π bond catalysis. Additionally, this catalytic reaction involves the endo pathway and exo pathway. The Gibbs free energy barrier values of the endo pathway are lower than those of the exo pathway, which facilitates the formation of the endo product. This study will provide a valuable perspective on the application of chalcogen bond in the activation of alkenes.
{"title":"Activation of Alkenes via Chalcogen Bond: Chalcogen•••π Bond Catalyzed the Diels-Alder Reaction of 2-Vinylindoles","authors":"Chang Zhao, Mengmeng Wang, Yanli Zeng","doi":"10.1002/ejoc.202401102","DOIUrl":"https://doi.org/10.1002/ejoc.202401102","url":null,"abstract":"Chalcogen bond catalysis is a promising catalytic strategy, characterized by its environmental friendliness, relatively inexpensive cost, and similar reactivity to transition metal catalysis. Experimental results suggest that the S•••π and Se•••π bonds can efficiently drive the vinyl-indole-based Diels-Alder reaction (Angew. Chem. Int. Ed. 2021, 60, 9395-9400). In this work, chalcogen bond catalysis in the Diels-Alder reaction between 2-vinylindoles has been investigated based on density functional theory. For this reaction, the Te•••π bond catalysis is as an alternative catalytic strategy. The Diels-Alder reaction catalyzed by chalcogen bond is stepwise and involves two steps: the carbon–carbon bond formation process and the cyclization process. The cyclization process is the rate-determining step. From the perspective of energy decomposition analysis, the electrostatic interaction is the main factor to cause Se•••π bond catalysis, the polarization interaction is the main factor to cause Te•••π bond catalysis. Additionally, this catalytic reaction involves the endo pathway and exo pathway. The Gibbs free energy barrier values of the endo pathway are lower than those of the exo pathway, which facilitates the formation of the endo product. This study will provide a valuable perspective on the application of chalcogen bond in the activation of alkenes.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rosalino Balo, Andrés Fernández, David Reza, Pablo López, George W. J. Fleet, Ramón J. Estévez, Juan C. Estévez
A synthesis of the iminosugar DAB and a divergent synthesis of 1-dehydromannojirimycin (DMJ) and the corresponding pipecolic acid are reported. The key step consists of double nucleophilic displacements of a D-xylose ditriflate by benzyl carbazate and a D-glucose ditriflate by allyl amine, respectively. This is followed by hydrolysis and oxidation or reduction of the resulting bicyclic glycosides.
本研究报道了亚氨基糖 DAB 的合成以及 1-脱氢丹诺尻霉素（DMJ）和相应哌啶醇酸的歧化合成。关键步骤包括肼基羧酸苄酯和烯丙基胺分别对 D-木糖二呋喃酸酯和 D-葡萄糖二呋喃酸酯的双亲核置换。然后对生成的双环苷进行水解、氧化或还原。
{"title":"Stable Ditriflates of D-Glucose in the Synthesis of Iminosugars and Polyhydroxylated Pipecolic Acids","authors":"Rosalino Balo, Andrés Fernández, David Reza, Pablo López, George W. J. Fleet, Ramón J. Estévez, Juan C. Estévez","doi":"10.1002/ejoc.202400395","DOIUrl":"https://doi.org/10.1002/ejoc.202400395","url":null,"abstract":"A synthesis of the iminosugar DAB and a divergent synthesis of 1-dehydromannojirimycin (DMJ) and the corresponding pipecolic acid are reported. The key step consists of double nucleophilic displacements of a D-xylose ditriflate by benzyl carbazate and a D-glucose ditriflate by allyl amine, respectively. This is followed by hydrolysis and oxidation or reduction of the resulting bicyclic glycosides.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142486434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Mahdavi, Fatemeh Doraghi, Mohammad Hossein Morshedsolouk, Samaneh Ghofrani, Bagher Larijani
N-Sulfonyl-1,2,3-triazoles are valuable precursors for the generation of α-imino carbene intermediates in the presence of the metal catalysts, especially rhodium(II) complexes. Due to the presence of electrophilic carbene and nucleophilic nitrogen, these reactive intermediates can easily be incorporated into many annulations, cycloadditions, C-H or O/N/S-H bond insertions and functionalization reactions. A large number of pharmaceutically important nitrogen-based building blocks can be constructed via this direct and atom-economical carbene strategy. In this review, we have described the transformations of N-sulfonyl-1,2,3-triazoles based on α-imino rhodium(II) carbene intermediates.
{"title":"Rhodium(II)-Catalyzed Denitrogenative Transformations of N-Sulfonyl-1,2,3-triazoles","authors":"Mohammad Mahdavi, Fatemeh Doraghi, Mohammad Hossein Morshedsolouk, Samaneh Ghofrani, Bagher Larijani","doi":"10.1002/ejoc.202401040","DOIUrl":"https://doi.org/10.1002/ejoc.202401040","url":null,"abstract":"N-Sulfonyl-1,2,3-triazoles are valuable precursors for the generation of α-imino carbene intermediates in the presence of the metal catalysts, especially rhodium(II) complexes. Due to the presence of electrophilic carbene and nucleophilic nitrogen, these reactive intermediates can easily be incorporated into many annulations, cycloadditions, C-H or O/N/S-H bond insertions and functionalization reactions. A large number of pharmaceutically important nitrogen-based building blocks can be constructed via this direct and atom-economical carbene strategy. In this review, we have described the transformations of N-sulfonyl-1,2,3-triazoles based on α-imino rhodium(II) carbene intermediates.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giulia Antonini, Laura Petrosilli, Ilaria Giussani, Maria Gessica Ciulla, Sarah Mazzotta, Giuseppe D'Orazio
The Front Cover shows domino transformations, which play a crucial role as chemical tools in drug discovery processes. In their Review (DOI: 10.1002/ejoc.202400511), S. Mazzotta, G. D'Orazio and co-workers showcase various instances of domino transformations applied to carbohydrates, with the goal of summarizing their chemical potential in producing sugar-derived compounds. These compounds have significant applications in generating new chemical scaffolds for drug discovery and chemical biology.
{"title":"Front Cover: Unleashing the Power of Domino Reactions on Carbohydrates: State of the Art (Eur. J. Org. Chem. 39/2024)","authors":"Giulia Antonini, Laura Petrosilli, Ilaria Giussani, Maria Gessica Ciulla, Sarah Mazzotta, Giuseppe D'Orazio","doi":"10.1002/ejoc.202483901","DOIUrl":"10.1002/ejoc.202483901","url":null,"abstract":"<p><b>The Front Cover</b> shows domino transformations, which play a crucial role as chemical tools in drug discovery processes. In their Review (DOI: 10.1002/ejoc.202400511), S. Mazzotta, G. D'Orazio and co-workers showcase various instances of domino transformations applied to carbohydrates, with the goal of summarizing their chemical potential in producing sugar-derived compounds. These compounds have significant applications in generating new chemical scaffolds for drug discovery and chemical biology.\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejoc.202483901","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brendan Horst, Leopoldo J. Gabella Carena, Michael T. Doppert, Rens Ham, Thomas Hansen, Eelco Ruijter
Based on the successful application of a nitroaryl transfer cascade reaction in the total synthesis of various monoterpene indole alkaloids proceeding via fused bicyclic intermediate, we investigated analogous cascade reactions involving spiro, bridged, and alternatively fused bicyclic intermediates. Unfortunately, none of these was found to afford the desired nitroaryl transfer product. DFT studies of the original cascade process revealed that the Truce-Smiles rearrangement is the rate-determining step. In addition, we found that the subsequent SO2 extrusion is accompanied by retro-Mannich ring opening, resulting in a stabilized enolate that only recyclizes after activation of the cyclic imine moiety. Computation of the reaction profiles of the proposed alternative cascade reactions showed that the barrier for the Truce-Smiles rearrangement is unreasonably high for the bridged and alternatively fused systems, but only moderately higher for the five-membered spiro system. Reasoning that even more electron-deficient arenesulfonamides should have a lower barrier for the Truce-Smiles rearrangement, we synthesized the corresponding 2,4-dinitrobenzenesulfonamide precursor and found that it indeed smoothly undergoes the nitroaryl transfer cascade at room temperature. In this case, however, the cascade reaction produces a cyclic imine product, as the intermediate 2,4-dinitrophenyl-substituted enolate is insufficiently nucleophilic to undergo the Mannich cyclization.
{"title":"Computation-Guided Scope Exploration of a Conjugate Addition/Truce-Smiles Cascade Reaction for Scaffold Diversification","authors":"Brendan Horst, Leopoldo J. Gabella Carena, Michael T. Doppert, Rens Ham, Thomas Hansen, Eelco Ruijter","doi":"10.1002/ejoc.202400870","DOIUrl":"https://doi.org/10.1002/ejoc.202400870","url":null,"abstract":"Based on the successful application of a nitroaryl transfer cascade reaction in the total synthesis of various monoterpene indole alkaloids proceeding via fused bicyclic intermediate, we investigated analogous cascade reactions involving spiro, bridged, and alternatively fused bicyclic intermediates. Unfortunately, none of these was found to afford the desired nitroaryl transfer product. DFT studies of the original cascade process revealed that the Truce-Smiles rearrangement is the rate-determining step. In addition, we found that the subsequent SO2 extrusion is accompanied by retro-Mannich ring opening, resulting in a stabilized enolate that only recyclizes after activation of the cyclic imine moiety. Computation of the reaction profiles of the proposed alternative cascade reactions showed that the barrier for the Truce-Smiles rearrangement is unreasonably high for the bridged and alternatively fused systems, but only moderately higher for the five-membered spiro system. Reasoning that even more electron-deficient arenesulfonamides should have a lower barrier for the Truce-Smiles rearrangement, we synthesized the corresponding 2,4-dinitrobenzenesulfonamide precursor and found that it indeed smoothly undergoes the nitroaryl transfer cascade at room temperature. In this case, however, the cascade reaction produces a cyclic imine product, as the intermediate 2,4-dinitrophenyl-substituted enolate is insufficiently nucleophilic to undergo the Mannich cyclization.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142452164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel and highly efficient methodology for the synthesis of 2,4,6-triaryl-1,3,5-triazines and 2,4,6-trisubstituted pyrimidines from amidines and alcohols has been established. Using the Earth-abundant and air-stable chromium salt catalyst and the phosphine-free ligand, the developed Cr-catalyzed acceptorless dehydrogenative coupling provides 1,3,5-triazines and pyrimidines with high yields and good functional group tolerance. Moreover, the synthetic value of this operationally simple protocol was demonstrated by gram-scale experiment and the synthesis of the linker to construct various supramolecular complexes.
{"title":"A Chromium Catalytic System for the Synthesis of Aryl-Substituted 1,3,5-Triazines and Pyrimidines by Acceptorless Dehydrogenative Coupling","authors":"Baojin Feng, Wantong Yue, Dongyue Wei, Qing Chen, Chuanqi Liu, Xiaoqian Wang, Yilei Wang, Zhihua Peng","doi":"10.1002/ejoc.202400993","DOIUrl":"https://doi.org/10.1002/ejoc.202400993","url":null,"abstract":"A novel and highly efficient methodology for the synthesis of 2,4,6-triaryl-1,3,5-triazines and 2,4,6-trisubstituted pyrimidines from amidines and alcohols has been established. Using the Earth-abundant and air-stable chromium salt catalyst and the phosphine-free ligand, the developed Cr-catalyzed acceptorless dehydrogenative coupling provides 1,3,5-triazines and pyrimidines with high yields and good functional group tolerance. Moreover, the synthetic value of this operationally simple protocol was demonstrated by gram-scale experiment and the synthesis of the linker to construct various supramolecular complexes.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robin Schulte, Dustin Schade, Thomas Paululat, Heiko Ihmels
The photochromic norbornadiene‐quadricyclane cycle has emerged as a promising basis for molecular solar thermal (MOST) energy storage. In this context, it has been established that multifunctional photoswitches with several norbornadiene units at one central aromatic core have favorable photochemical properties and storage capacities. Nevertheless, a maximum number of three norbornadiene units has been combined in one molecule, so far. In this work, scope and limits of this approach should be further assessed. Thus, exemplary polyfunctionalized derivatives have been synthesized by Suzuki‐Miyaura reactions, and their suitability for MOST applications was investigated. These compounds were converted into the corresponding quadricyclanes by direct UV irradiation (λex = 315 nm) with moderate quantum yields, whereas the reaction is more efficient upon irradiation with λex = 520 nm in the presence of photosensitizers. But these molecules showed low stabilities and short half‐lifes of 1 to 2 days. Moreover, the photochemical reaction is hampered by the close vicinity of photoactive units. Therefore, it appears that in such assemblies, a maximum number of three norbornadiene units is the limit to keep the optimal balance of photochemical properties required for MOST applications.
光致变色降冰片二烯-四环烷循环已成为分子太阳能热（MOST）储能的一个有前途的基础。在这种情况下，已经证实在一个芳香族中心核上含有多个降冰片二烯单元的多功能光开关具有良好的光化学特性和储能能力。不过，迄今为止，在一个分子中最多只能结合三个降冰片二烯单元。在这项工作中，应进一步评估这种方法的范围和局限性。因此，我们通过 Suzuki-Miyaura 反应合成了多官能化衍生物，并研究了它们在 MOST 应用中的适用性。通过紫外线直接照射（λex = 315 纳米），这些化合物转化为相应的四环化合物，量子产率适中，而在光敏剂存在的情况下，用 λex = 520 纳米照射，反应效率更高。但这些分子的稳定性较低，半衰期较短，仅为 1 到 2 天。此外，光化学反应还受到光活性单元邻近的阻碍。因此，在这种组合物中，要保持 MOST 应用所需的光化学特性的最佳平衡，最多只能有三个降冰片二烯单元。
{"title":"Gilding the Lily: Studies on the Effects of Successive Loading of Light Energy‐Storing Molecules with Norbornadiene Units","authors":"Robin Schulte, Dustin Schade, Thomas Paululat, Heiko Ihmels","doi":"10.1002/ejoc.202401090","DOIUrl":"https://doi.org/10.1002/ejoc.202401090","url":null,"abstract":"The photochromic norbornadiene‐quadricyclane cycle has emerged as a promising basis for molecular solar thermal (MOST) energy storage. In this context, it has been established that multifunctional photoswitches with several norbornadiene units at one central aromatic core have favorable photochemical properties and storage capacities. Nevertheless, a maximum number of three norbornadiene units has been combined in one molecule, so far. In this work, scope and limits of this approach should be further assessed. Thus, exemplary polyfunctionalized derivatives have been synthesized by Suzuki‐Miyaura reactions, and their suitability for MOST applications was investigated. These compounds were converted into the corresponding quadricyclanes by direct UV irradiation (λex = 315 nm) with moderate quantum yields, whereas the reaction is more efficient upon irradiation with λex = 520 nm in the presence of photosensitizers. But these molecules showed low stabilities and short half‐lifes of 1 to 2 days. Moreover, the photochemical reaction is hampered by the close vicinity of photoactive units. Therefore, it appears that in such assemblies, a maximum number of three norbornadiene units is the limit to keep the optimal balance of photochemical properties required for MOST applications.","PeriodicalId":167,"journal":{"name":"European Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142449457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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