Article
Chemistry, Physical
Michael M. M. Gilbert, Michael J. J. Trenerry, Victoria R. R. Longley, Anthony J. J. Castro, John F. F. Berry, Daniel J. J. Weix
Summary: Cyclopropyl ketones can be cross-coupled with organozinc reagents and chlorotrimethylsilane to form 1,3-difunctionalized, ring-opened products. The redox-active terpyridine ligand and the nickel atom cooperate to enable the C-C bond activation step. This approach allows for quick access to difficult-to-make products.
Article
Chemistry, Organic
Paul Shaw, Storm J. Hassell-Hart, Gayle E. Douglas, Andrew G. Malcolm, Alan R. Kennedy, Gemma White, Laura C. Paterson, William J. Kerr
Summary: In this study, we applied silyl enol ether moieties as efficient alkene coupling partners within cobalt-mediated intramolecular Pauson-Khand reactions. This cyclization strategy delivers valuable oxygenated cyclopentenone products in high yields and allows for the incorporation of a variety of decorated structures.
Article
Chemistry, Multidisciplinary
Dongxin Zhang, Lvjia Chen, Huiqing Deng, Ying Zhang, Qihang Cheng, Qian-Feng Zhang
Summary: Asymmetric ring-opening reactions of donor-acceptor cyclopropanes with 1,3-cyclodiones have been achieved for the synthesis of enantioenriched gamma-hydroxybutyric acid derivatives in the presence of Cu(ii)/trisoxazoline catalyst. These reactions provided the desired products in yields of 70% to 93% with enantiomeric excesses of 79% to 99%.
Article
Chemistry, Physical
Bing Yuan, Decai Ding, Chuan Wang
Summary: In this study, we have successfully implemented a reductive strategy for the ring opening reaction of aryl cyclopropylketones with unactivated alkyl bromides. The nickel-catalyzed reductive Csp3-Csp3cross-coupling reaction proceeds with complete regioselectivity, bypassing the need for pregenerated organometallics and allowing for efficient synthesis of alkylated ketones with high step economy and functionality tolerance.
Review
Chemistry, Organic
Sudheesh T. Sivanandan, R. Bharath Krishna, Thekke V. Baiju, Chithra Mohan
Summary: The high reactivity of cyclopropanes has led to the development of various methods for their stereo- and regio-controlled ring-opening reactions. Visible-light-mediated photoredox reactions have gained significant attention in recent years for organic transformations, including ring-opening reactions of cyclopropanes. Multiple methodologies have been developed under visible-light photoredox catalysis for cyclopropane ring-opening reactions, showcasing the synthetic potential of this class of reactions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Review
Biochemistry & Molecular Biology
Taku Shoji, Shunji Ito, Masafumi Yasunami
Summary: Various synthetic methods have been developed for azulene derivatives, with 2H-cyclohepta[b]furan-2-one and its derivatives being commonly used as precursors. The synthesis of azulenes involves reactions with olefins, active methylenes, enamines, and silyl enol ethers, with resulting compounds showing promising applications.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Vincent Pirenne, Emma G. L. Robert, Jerome Waser
Summary: Efficient catalytic activation of donor-acceptor aminocyclopropanes lacking the commonly used diester acceptor was achieved in a (3 + 2) dearomative annulation with indoles, yielding cycloadducts in high yields and high diastereomeric ratios, leading to tricyclic indoline frameworks containing four stereogenic centers.
Article
Chemistry, Physical
Damiano Tanini, Tommaso Pecchi, Nikolai Ignat'ev, Antonella Capperucci
Summary: The ring opening reactions of strained heterocycles can be efficiently carried out in ionic liquids using silyl chalcogenides, resulting in the synthesis of beta-functionalized sulfides and selenides under mild conditions.
Article
Chemistry, Multidisciplinary
Aleksandra Blocka, Jakub Ostapko, Wojciech Chaladaj
Summary: For the first time, a cascade reaction involving a 5-exo-dig intramolecular nucleophilic addition of an enamine to a terminal alkyne followed by cross coupling has been demonstrated. This reaction allows for the stereoselective formation of two new C-C bonds using a single Pd-complex capable of catalyzing two mechanistically diverse transformations. Mechanistic investigations revealed that cyclization, relying on the facile displacement of OTf weakly bound to the Pd-center by the alkyne, is the rate limiting step.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Mohit Tyagi, Dan E. Adolfsson, Pardeep Singh, Joergen Aden, Sanduni Wasana Jayaweera, Anna Gharibyan, Jaideep B. Bharate, Anita Kiss, Souvik Sarkar, Anders Olofsson, Fredrik Almqvist
Summary: A novel method for synthesizing cyclobutane fused thiazolino-2-pyridones was discovered, some of which showed inhibitory effects on protein fibril formation, while others were able to bind to different proteins. Several bioactive compounds tolerated this synthetic method, while also providing a potential handle for tuning bioactivity.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Het Vyas, Ashvin J. Gangani, Aiswarya Mini, Shengjia Lin, Jia-Min Chu, Caitlyn O. Agee, Justin Gabriel, R. Thomas Williamson, Yong Zhang, Abhishek Sharma
Summary: This study reports the development of vinyl cyclopropyl diborons (VCPDBs) as a versatile source of previously unknown homoallylic alpha,alpha-diboryl radicals via thiyl radical catalyzed diboron-directed ring opening. These diboryl stabilized radicals underwent smooth [3+2] cycloaddition with a variety of olefins to provide diboryl cyclopentanes in good to excellent diastereoselectivity. The mild reaction conditions also allowed a one-pot VCP ring-opening, cycloaddition-oxidation sequence to afford disubstituted cyclopentanones. Control experiments and DFT analysis of reaction mechanism support a radical mediated pathway and provide a rationale for the observed diastereoselectivity. To the authors' knowledge, these are the first examples of the use of geminal diboryl group as an activator of VCP ring opening and cycloaddition reaction of alpha-boryl radicals.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Xiaowu Fang, Songwei Wen, Peishen Jin, Wenjing Bao, Shanshan Liu, Hengjiang Cong, Xiao Shen
Summary: Fluorinated enol silanes are widely used in synthetic transformations, but previous methods only allowed for the synthesis of racemic products. In this study, an enantioselective reductive coupling reaction was developed to access enantioenriched fluorinated enol silanes. The practicality of this methodology was demonstrated through multistep-one-isolation processes, and the synthetic potential of enantioenriched fluorinated enol silanes in the synthesis of valuable chiral organofluorine compounds was also shown.
Article
Chemistry, Multidisciplinary
Anthony Cohen, Alexander Kaushansky, Ilan Marek
Summary: This study presents the preparation of a new class of alkenyl cyclopropyl diols through a copper-catalyzed carbometalation reaction. The investigation sheds light on the mechanistic aspects of the tandem Heck-cyclopropane ring-opening reaction and reveals the roles of hydroxyl groups in controlling the regio- and stereoselectivity. Furthermore, the reaction provides a convenient method for synthesizing lactones with multiple stereocenters.
Article
Chemistry, Organic
Masayuki Kirihara, You Kikkawa, Riho Nakamura, Kana Nakakura, Yasuhiro Suzuki, Yukari Muramatsu
Summary: The reaction between cyclopropylmethanols bearing aromatic substituents on their cyclopropane rings and diethylaminosulfur trifluoride (DAST) effectively resulted in ring-opening fluorination to produce homoallylic fluorides. This reaction proceeds via a carbocation intermediate. Moreover, DAST reacted with cyclopropanecarbaldehydes containing electron donating aromatic substituents to cause ring-opening fluorinations with the addition of two fluorine atoms, giving 1,4-difluorobut-1-enes as the final products.
TETRAHEDRON LETTERS
(2021)
Article
Chemistry, Organic
Xu Li, Lu Lanlan, Wang Xiangshan
Summary: A method for the rapid synthesis of beta-keto sulfones catalyzed by copper bromide from enol silyl ether and sodium arylsulfinates has been developed, which offers the advantages of simple operation, mild conditions, and short reaction time.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
