Article
Chemistry, Applied
Patricia Garcia-Martinez, Olaya Bernardo, Javier Borge, Javier Gonzalez, Luis A. Lopez
Summary: The BF3 & sdot;OEt2-catalyzed reaction of azulene with N-protected aziridines provides a general and efficient method for synthesizing phenethylamine-azulene conjugates with high regioselectivity (up to 91% yield). Stereochemical studies and DFT calculations confirm a concerted SN2-type mechanism for the ring-opening reaction of aziridine.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Aleksandra Potrzasaj, Mateusz Musiejuk, Wojciech Chaladaj, Maciej Giedyk, Dorota Gryko
Summary: This study presents a method for the selective synthesis of linear products from epoxides using a vitamin B-12/Ni dual-catalytic system. This method complements approaches that provide branched alcohols and relies on blue-light irradiation for the reaction to occur. Both experimental and theoretical studies support the proposed mechanism involving alkylcobalamin as an intermediate in this process.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Zhi-Yuan Zhao, Ming Cui, Elisabeth Irran, Martin Oestreich
Summary: This study successfully achieved highly enantioselective silylation of 3-substituted 2H-azirines using a copper-catalyzed reaction with a silyl boronic ester as a latent silicon nucleophile. The resulting C-silylated, unprotected (N-H) aziridines were obtained in high yields and with excellent enantioselectivities, and they can be further converted into valuable compounds without significant loss of enantiomeric excess.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Lantao Liu, Fangyuan Cheng, Chenxiang Meng, An-An Zhang, Mingliang Zhang, Kai Xu, Naoki Ishida, Masahiro Murakami
Summary: A Pd-catalyzed chemo-, regio-, and enantioselective ring-closing/ring-opening cross coupling reaction has been developed with diverse aryl halide-tethered alkenes and benzocyclobutenols as substrates. This method provides a convenient approach to chiral 2,3-dihydrobenzofurans with excellent enantioselectivities, and has been applied in the concise synthesis of analogues of cannabinoid receptor 2 agonists.
Article
Chemistry, Multidisciplinary
Vibha V. Kanale, Christopher Uyeda
Summary: Cobalt catalysts facilitate highly enantioselective ring-opening reactions of 2,5-dihydrofurans using vinylidenes. The resulting products are acyclic organozinc compounds, capable of further functionalization with an electrophile. The proposed mechanism involves the formation of a cobalt vinylidene species that adds to the alkene via a [2+2]-cycloaddition pathway, followed by ring-opening through outer-sphere & beta;-O elimination assisted by a ZnX2 Lewis acid. DFT models explain the observed stereochemical outcome by suppressing competing inner-sphere syn & beta;-H and & beta;-O elimination pathways due to the geometric constraints of the metallacycle intermediate. Cobalt catalysts also promote enantioselective ring-opening reactions of unstrained heterocycles via reductive addition of 1,1-dichloroalkenes. The resulting products are acyclic homoallylic alcohols with a vinylzinc motif, which can be further modified with an electrophile. Mechanistic studies suggest that the ring-opening occurs through outer-sphere & beta;-O elimination facilitated by a Zn(II) Lewis acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Polymer Science
Huishan Huang, Wenyi Luo, Linlin Zhu, Ying Wang, Zhen Zhang
Summary: An organocatalytic sequential ring-opening polymerization approach was developed for the synthesis of polysulfonamide-based copolymers, allowing for precise control of molar masses and dispersities. The method involves the use of alcohols and methoxylpolyethylene glycols as initiators, followed by tosyl isocyanate-mediated transformations and ROP reactions. Well-defined triblock and star-shaped copolymers can be successfully prepared from diol and triol initiators.
Article
Chemistry, Physical
Abdoul G. Diallo, Deborah Paris, Djiby Faye, Sylvain Gaillard, Mark Lautens, Jean-Luc Renaud
Summary: This study reports a general approach for the allylation of oxa- and azabenzonorbornadienes by merging organophotoredox and nickel catalysis. The method allows for selective allylation of various heterocyclic alkene derivatives with a broader range of allylic acetate compounds. Notably, the reaction does not require air-sensitive organometallic species or metal reductants.
Article
Biochemistry & Molecular Biology
Lucilla Favero, Andrea Menichetti, Cosimo Boldrini, Lucrezia Margherita Comparini, Valeria Di Bussolo, Sebastiano Di Pietro, Mauro Pineschi
Summary: The study reveals the structural requirements and reaction conditions for regioselective nucleophilic addition reaction on alkyl aziridines using bis(pinacolate)diboron under copper catalysis. This is important for the preparation of functionalized beta-aminoboronates, which are key compounds in drug discovery.
Article
Chemistry, Multidisciplinary
Meng Huo, Yawen Bian, Chunyang Yu, Gangsheng Tong, Chongyin Zhang, Xinyuan Zhu
Summary: This study presents an AROP method for N-sulfonyl aziridines that can be operated in air environment using sulfanions as initiators. Open-vessel polymerization resulted in a range of polymers with high livingness and narrow molecular weight distributions, enabling further post-polymerization functionalization.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Applied
Siyang Xing, Hanyu Xia, Chenyu Wang, Yuhan Wang, Lu Hao, Kui Wang, Bolin Zhu
Summary: A new type of 2,2-disubstituted N-sulfonylaziridines has been prepared, featuring OTBS groups and aryl groups. A stepwise strategy involving ring opening of aziridines and C-H activation/cyclization has been developed for the general synthesis of spiroindoline pyrans and spiroindoline furans.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Physical
Zhe-Ran Chang, Si-Si Du, Cui Zhang, Shuang-Hu Chen, Yuan-Zhao Hua, Min-Can Wang, Guang-Jian Mei, Shi-Kun Jia
Summary: An efficient kinetic resolution of racemic trans-2,3-aziridinyl alcohols is achieved through zinc catalyzed ring opening reactions with different amines as nucleophiles. The directing effect of the hydroxyl group and the precise enantiodiscrimination by a dinuclear zinc cooperative catalyst are crucial for high regioselectivity and enantioselectivity. Various enantioenriched vicinal diamines and trans-2,3-aziridinyl alcohols are obtained in good yields with excellent ee values. This study represents the first example of directed enantioselective nucleophilic ring opening reactions of 2,3-aziridinyl alcohols.
Article
Chemistry, Multidisciplinary
Kun Zhao, Shan Yang, Qi Gong, Longhui Duan, Zhenhua Gu
Summary: A Cu-catalyzed enantioselective ring-opening alkoxygenation reaction of cyclic diaryliodonium salts and diols was reported, with borinic acids playing a key role in selectively activating different types of diols. The proposed catalytic cycle involves a key ion pair model to account for the observed enantioselectivity. This study provides insights into the design of chiral catalysts for selective synthesis of cyclic molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Ling Qi, Pei-Jun Yang, Wen-Tao Ji, Gui-De Tao, Gaosheng Yang, Zhuo Chai
Summary: In this study, we report an efficient strategy for synthesizing compounds with high pharmaceutical value using catalysts. The method is simple and feasible, with mild reaction conditions, and can be used for the synthesis of important drugs.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Polymer Science
Chandan Giri, Sarah E. Sisk, Louis Reisman, Irshad Kammakakam, Jason E. Bara, Kevin N. West, Brooks D. Rabideau, Paul A. Rupar
Summary: The study explores the anionic ring-opening polymerization of sulfonylaziridines in ionic liquids. In imidazolium ILs, the polymerization is not controlled due to poor solubility and solvent-transfer reactions, while in phosphonium ILs, it is controlled and living, allowing for sequential block copolymer synthesis. The slower polymerization rates in ILs compared to traditional polar solvents like DMF may be attributed to better monomer/anion organization in DMF and poorer mobilities in ILs.
Article
Chemistry, Organic
Joseph P. Milton, John S. Fossey
Summary: This article discusses the asymmetric catalytic applications of chiral azetidine-derived ligands and organocatalysts since the early 1990s, highlighting the effective synthetic opportunities they provide. It also compares and evaluates these asymmetric catalysts with aziridine- and pyrrolidine-containing analogues.