Article
Chemistry, Multidisciplinary
Wai Fung Cheng, Shiqiang Ma, Yin Tung Lai, Yuen Tsz Cheung, Kornkamon Akkarasereenon, Yiqin Zhou, Rongbiao Tong
Summary: An intramolecular aza-Prins cyclization of aza-Achmatowicz rearrangement products was developed using bismuth tribromide as both an efficient Lewis acid and a bromide nucleophile source. This approach enables the construction of highly functionalized 9-azabicyclo[3.3.1]nonanes, which are valuable building blocks for alkaloid natural products and drug molecules. The application of this method to the total synthesis of six indole alkaloids demonstrates its significant synthetic utility.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Na Li, Qian Wang, Shuping Zhuo, Li-Ping Xu
Summary: The mechanism, reactivity, and selectivity of the aza-Prins reaction were studied using theoretical calculations, both in bulk solution and under [Ga4L6](12-) supramolecular catalysis. In bulk solution, the steric effect and donor-acceptor interaction favor the parallel-conformation transition state, leading to the observed chemoselectivity that produces the alcohol product. However, under [Ga4L6](12-) catalysis, the host-guest noncovalent interaction and confinement effect play a more critical role, leading to the vertical-conformation transition state and switch in chemoselectivity that produces the piperidine product. These computational findings are consistent with experimental results and provide insights into the development of more efficient and selective supramolecular catalysis.
Article
Chemistry, Medicinal
Jose A. Galvez, Ramon Badorrey, Alejandro Mahia, Maria D. Diaz-de-Villegas
Summary: The synthesis of (1R,5S)-2-methyl-6,7-benzomorphan from (R)-(benzyloxy)(phenyl)acetaldehyde involved a series of reactions including Aza-Prins reaction, high-yielding sequence reactions, and acid-catalysed intramolecular Friedel-Crafts cyclisation to achieve a yield of 25%.
Article
Chemistry, Organic
Mayur D. Ambule, Mandweep Bhumij, Asheesh Kumar, Ruchir Kant, Ajay Kumar Srivastava
Summary: Post-Ugi modifications provide an atom-economic approach to construct functionalized heterocycles. In this study, we demonstrated the synthesis of highly functionalized azaspiro tricyclic scaffolds through Ugi condensation, ipso-cyclization, and aza-Michael ring closures. We also investigated the substrate scope and limitations of aza-Michael cyclizations and developed new methods for the preparation of novel azaspiro tricyclic scaffolds.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Haibo Xu, Shengming Ma
Summary: An efficient method for synthesizing benzazocines through a double allene protocol has been developed. The reaction involves a highly selective palladium-catalyzed formal [6+2] annulation of allenyl benzoxazinanones with terminal allenes, resulting in the formation of challenging 8-membered cycles. The reaction exhibited decent yields, excellent regioselectivity, and remarkable Z-stereoselectivity for the exo-cyclic C=C bonds. The synthetic potential of benzazocine products has been demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Organic
Keyvan Pedrood, Mohammad Nazari Montazer, Bagher Larijani, Mohammad Mahdavi
Summary: This review summarizes recent studies on heterocyclic compounds focusing on the formation of the C=N bond via the aza-Wittig reaction. It also discusses two different strategies for forming heterocyclic compounds and provides up-to-date information on the synthesis of various N-containing heterocyclic compounds using the aza-Wittig reaction in chemical literature since 2010.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Applied
Alexandre Bergounioux, Romane Lhotellier, Thierry Roisnel, Nicolas Gouault, Gilles Argouarch, Claudia Lalli
Summary: The aza-Prins cyclization in presence of various aliphatic, aromatic, and heterocyclic ketones has been described. This method provides access to a range of C-2 functionalized piperidines, with a tetrasubstituted or spiranic carbon stereocenter, in yields ranging from 30% to 87%. When diastereomers were formed, the trans isomer was identified as the major product.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Yong You, Guo-Ying Gan, Si-Yang Duan, Yan-Ping Zhang, Qun Li, Zhen-Hua Wang, Jian-Qiang Zhao, Xiong-Li Liu, Wei-Cheng Yuan
Summary: A highly enantioselective aza-Friedel-Crafts reaction was established for the synthesis of chiral tryptanthrin derivatives using chiral phosphoric acid as a catalyst. The synthesized compounds exhibited excellent yields and good to excellent enantioselectivities, and showed potential for medicinal applications, particularly in the treatment of leukemia.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Takeo Sakai, Tomoki Furuhata, Kota Hosoe, Kaho Umemura, Yuji Mori
Summary: A novel cascade reaction involving alkylation, cyclization, isomerization, and 3-aza-Cope rearrangement was developed. The chiral centers of the starting piperidines were transferred to the bicyclic enamine products, and a wide range of electron-withdrawing groups on the alkyne moieties were tolerated. The resulting bicyclic enamines underwent cyclization mediated by trifluoroacetic acid (TFA) to produce tricyclic amines with tetrasubstituted carbons.
Article
Chemistry, Multidisciplinary
Natalie C. Dwulet, Zeinab Chahine, Karine G. Le Roch, Christopher D. Vanderwal
Summary: We have successfully synthesized the rare isocyanoterpene natural product isoneoamphilectane and its two unnatural diastereomers. Our initial hypothesis about a misassignment in the structure's relative configuration led us to target two less-strained stereoisomers, but they did not match the spectroscopic data of isoneoamphilectane. We then embarked on a challenging synthesis of the originally proposed strained structure, guided by computational analyses to control stereochemistry.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Applied
Mina Rajabi, Jaydee Cabral, Sarah Saunderson, M. Azam Ali
Summary: Chitooligosaccharide (COS), an emerging material carbohydrate polymer, was prepared using a microwave-assisted process. The COS was then used to synthesize COS-poly(ethylene glycol) diacrylate (PEGDA) derivatives through aza-Michael addition. The resulting COS-PEGDA hydrogels showed high biocompatibility and can be potentially used in biomedical applications.
CARBOHYDRATE POLYMERS
(2022)
Article
Chemistry, Organic
Lucas A. Zeoly, Lais V. Acconcia, Manoel T. Rodrigues Jr, Hugo Santos, Rodrigo A. Cormanich, Juan C. Paniagua, Albert Moyano, Fernando Coelho
Summary: This article describes a one-pot approach for the synthesis of tricyclic indolizines using a bicyclic imidazole-alcohol catalyst. The method is based on an aqueous Morita-Baylis-Hillman reaction, followed by intramolecular cyclization and dehydration, resulting in the formation of two new bonds (C-C and C-N) in simple conditions. The cyclization efficiency depends on the size of the cycloalkenone ring.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Applied
Ivan Aguas, Maria Jose Hidalgo, Aida Luz Villa, Edwin A. Alarcon
Summary: The synthesis of homolimonenol using heterogeneous tin-based catalysts was reported for the first time. The Sn-SBA-15 catalyst showed the best conversion, selectivity, and TOF, and it maintained its activity after five repeated uses. Moreover, when scaling up the reaction, a high conversion of limonene and selectivity to homolimonenol were obtained.
Article
Chemistry, Organic
Sho Amemiya, Shingo Okemoto, Akira Tsubouchi, Akio Saito
Summary: A synthetic method for alpha-(aminoethyl)-alpha,beta-enones from aryl-substituted homopropargyl sulfonamides and aldehydes was developed, representing the first synthesis of conjugated enones via alkyne aza-Prins cyclization. These products could be further converted into pyrrolidines.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Physical
A. Yu Sidorenko, Yu M. Kurban, I. Il'ina, N. S. Li-Zhulanov, D. Korchagina, O. Ardashov, J. Warna, K. P. Volcho, N. F. Salakhutdinov, D. Yu Murzin, V. E. Agabekov
Summary: In this study, condensation of a-pinene derived p-menta-1,8-diene-5,6-diol with decanal was carried out for the first time over modified halloysite nanotubes as the catalyst, resulting in a high and stable yield of the desired product. The halloysite nanocatalysts exhibited good selectivity towards the target product and higher activity when reacting with a set of carbonyl compounds.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Physical
Yuichi Akiyama, Yuichiro Mutoh, Kyosuke Isoda
Summary: The designed site-selective acid sensing liquid ThioBzL based on an asymmetric N-heteroacene framework shows differentiated acid sensing properties for the two imino-N atoms due to asymmetric substitution of pi-conjugated rings. The intramolecular interaction between the S atom of thiophene and the imino-N atom on the thiophene side promotes the site-selective acid sensing of the imino-N atom on the benzene side. Additionally, the emission colors of ThioBzL can be repeatedly controlled by exposing to HCl and NH3 vapor.
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
(2021)
Article
Chemistry, Physical
Yuika Sato, Yuichiro Mutoh, Shuhei Morishita, Noriaki Tsurumachi, Kyosuke Isoda
Summary: In this study, a stimulus-responsive supercooled pi-conjugated liquid was reported, showing potential for application in rewritable media. The dramatic color change in photoluminescence from yellow to green upon solidification was demonstrated through fluorescence spectra and lifetime decay profiles.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Yuichiro Mutoh, Kensuke Yamamoto, Yusei Mohara, Shinichi Saito
Summary: Efforts were made to develop a ruthenium complex for efficient catalysis of the hydrosilylation and hydroboration of terminal alkynes, as well as to explore factors controlling the (Z)-selectivity of the reactions. Additionally, the activation of B-protected boronic acids, R-B(dan) (dan = naphthalene-1,8-diaminato), believed to not participate in Suzuki-Miyaura cross-coupling, was discussed.
Article
Chemistry, Physical
Shiyu Tamaki, Yuichiro Mutoh, Kyosuke Isoda
Summary: The synthesis and characterization of benzoquinone derivatives BQ, BQ2, and BQ4 were conducted, with BQ4 self-assembling into a hexagonal columnar liquid-crystalline phase over a wide temperature range and BQ2 forming a crystal structure. Single crystal X-ray analysis revealed that the molecular arrangement of benzoquinone cores in BQ4 prevents interaction, leading to columnar structures.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Organic
Shinichi Saito, Tomohiro Katamura, Rei Tsukazaki, Akito Fujisawa, Yusuke Yoshigoe, Yuichiro Mutoh
Summary: The aza-Prins reaction of 6,7-dimethoxy-3-vinyl-1,2,3,4-tetrahydroquinoline with 1,2-dicarbonyl compounds in the presence of HCl yielded tricyclic benzazocines in 20-86% yield. The reaction showed stereoselectivity, producing the 2,4-trans isomer. Reacting 1 with an enantiopure ketoester gave two diastereomers, which could be easily separated and converted to enantiopure tricyclic benzazocines. Additionally, spirooxindole derivatives were synthesized by reacting 1 with isatin derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Yusuke Kawasaki, Showkat Rashid, Katsuhiko Ikeyatsu, Yuichiro Mutoh, Yusukc Yoshigoe, Simko Kikkawa, Isao Azumaya, Shoichi Hosoya, Shinichi Saito
Summary: In this study, a series of [2]rotaxanes with various functional groups in the axle component were synthesized through the oxidativedimerization of alkynes mediated by a macrocyclic phenanthroline-Cu complex. The rotaxanes were fully characterized and the structure of one rotaxane was determined by X-ray crystallographic analysis. The interaction between the ring component and the axle component was studied in detail, revealing that the presence of a hydrogen bond between the phenanthroline moiety in the macrocyclic component and the acidic proton in the axle component influenced the conformation of the rotaxane.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Showkat Rashid, Takashi Murakami, Hiroshi Koganezawa, Yusuke Yoshigoe, Shoichi Hosoya, Shinichi Saito
Summary: Oxidative dimerization of terminal alkynes (Glaser coupling) triggered by spirofluorene derived macrocyclic phenanthroline-Cu complexes was used to synthesize a series of novel [2]rotaxanes. The size and structural variations among the components and their effects on the dynamic behavior were investigated in detail using H-1 and F-19 NMR spectroscopy. Non-symmetric distribution of the ring component along the axle component was observed in the NMR spectra of rotaxanes with substituted macrocyclic components with low symmetry, and localization of the ring component near the 1,3-diyne moiety was observed in some [2]rotaxanes.
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Organic
Taiga Yasuda, Yusuke Yoshigoe, Shinichi Saito
Summary: This paper reports a concise synthesis of 1,8-diaminonaphthalene-protected diboronic acid (B2(dan)2), which is a promising borylating agent. B2(dan)2 is a stable compound that can be used for Cu-catalyzed borylation of styrene derivatives. The reaction shows high selectivity, and the products have yields up to 97%. Mechanistic studies suggest that a borate species is a key intermediate for the borylation reaction.
Article
Chemistry, Inorganic & Nuclear
Yusuke Yoshigoe, Keiichiro Hashizume, Shinichi Saito
Summary: Chiral aza-boraspirobifluorenes were synthesized and their structural and photophysical properties were evaluated. Enantiomers were separated by chiral HPLC and the absolute stereochemistry was determined. The racemization rate-determining step was found to involve the cleavage of the B-N bond.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Yusuke Yoshigoe, Yohei Tanji, Yusei Hata, Kohtaro Osakada, Shinichi Saito, Eiichi Kayahara, Shigeru Yamago, Yoshitaka Tsuchido, Hidetoshi Kawai
Summary: Different ligands can selectively generate different shapes of gold complexes. The dcpm ligand can accelerate the exchange reaction of Au(I)-CΣ bond to produce triangular macrocydic complexes. Additionally, the oxidative chlorination of the macrocydic gold complexes can yield a series of [n]cycloparaphenylenes in high yields.
Review
Chemistry, Multidisciplinary
Showkat Rashid, Yusuke Yoshigoe, Shinichi Saito
Summary: Advancements in mechanically interlocked molecular systems (MIMs) have reshaped the landscape of material chemistry and provided opportunities for exploring new applications and creating diversity. Among these molecular entities, rotaxanes have gained special attention in the field of supramolecular chemistry. This review aims to document the contemporary developments in the synthesis and applications of phenanthroline (phen) based rotaxanes.
Article
Chemistry, Inorganic & Nuclear
Chi-Wai Fung, Go Fukada, Yuichiro Mutoh, Noriko Tsuchida, Shinichi Saito
DALTON TRANSACTIONS
(2020)
