Results 1 to 10 of about 98,610 (164)
Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis [PDF]
Beilstein Journal of Organic ChemistryTerpenoids exhibit remarkable structural diversity, including highly complex ring-expanded or contracted carbocyclic skeletons. This review aims to explore intriguing examples of such ring-size alterations in all aspects of terpenoid synthesis.
Nicolas Kratena +2 more
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Ring expansion of osmacyclopentadiene affords diverse six-membered osmaaromatics [PDF]
Communications ChemistryMetallaromatics such as metallabenzene and its heteroatom-containing analogues have aroused interests both in experimental and theoretical studies. While various six-membered metallaaromatics have been explored, a general synthetic methodology is still ...
Yue Zhao +4 more
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Selective ring expansion and C−H functionalization of azulenes [PDF]
Nature Communications, 2023 We report a transition metal-catalyzed ring expansion of azulene that can be contrasted with C–H functionalization. This study represents the first example of the successful ring expansion of azulene using Cu(hfacac)2 (hfacac: hexafluoroacetylacetonate ...
Sangjune Park +7 more
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Medium-Sized Ring Expansion Strategies: Enhancing Small-Molecule Library Development [PDF]
MoleculesThe construction of a small molecule library that includes compounds with medium-sized rings is increasingly essential in drug discovery. These compounds are essential for identifying novel therapeutic agents capable of targeting “undruggable” targets ...
Hwiyeong Lee, Jonghoon Kim, Minseob Koh
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Expansivity on commutative rings [PDF]
Topology and its Applications, 2020 In this article we extend the notion of expansivity from topological dynamics to automorphisms of commutative rings with identity. We show that a ring admits a 0-expansive automorphism if and only if it is a finite product of local rings. Generalizing a well known result of compact metric spaces, we prove that if a ring admits a positively expansive ...
Alfonso Artigue, Mariana Haim
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Molecules, 2023 A Lewis acid-promoted annulation of azadienes and cyclobutamines was developed. This reaction proceeded through Michael addition and ring-expansion cascade, affording the corresponding nitrogen-containing medium-sized rings with a broad scope in moderate
Jiaming Wang, Jia Li, Changgui Zhao
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Hydrazides in the reaction with hydroxypyrrolines: less nucleophilicity – more diversity
Beilstein Journal of Organic Chemistry, 2021 Expedient protocols for the synthesis of three types of highly functionalized azaheterocyclic scaffolds (dihydropyridazines, tetrahydropyridazines, and partially saturated tricyclic systems) from readily available hydroxypyrrolines and hydrazides are ...
Dmitrii A. Shabalin +4 more
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Molecules, 2023 This study presents the development of a mechanochemical protocol for a charge-accelerated aza-Claisen rearrangement. The protocol waives the use of commonly applied transition metals, ligands, or pyrophoric Lewis acids, e.g., AlMe3.
Christian Schumacher +5 more
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Dearomative Ring Expansion of Polycyclic Arenes [PDF]
Angewandte Chemie - International Edition, 2022 Tanner W Bingham, David Šarlah
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Methanol-Driven Oxidative Rearrangement of Biogenic Furans – Enzyme Cascades vs. Photobiocatalysis
Frontiers in Chemistry, 2021 The oxidative ring expansion of bio-derived furfuryl alcohols to densely functionalized six-membered O-heterocycles represents an attractive strategy in the growing network of valorization routes to synthetic building blocks out of the lignocellulosic ...
Christina Jäger +5 more
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