Controlled functionalization ofo-carboraneviatransition metal catalyzed B–H activation

Chemical Society Reviews, Journal Year: 2019, Volume and Issue: 48(13), P. 3660 - 3673

Published: Jan. 1, 2019

This review summarizes recent advances in transition metal catalyzed vertex-specific BH functionalization ofo-carborane for controlled synthesis of its derivatives.

Language: Английский

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Molecular Main Group Metal Hydrides

Chemical Reviews, Journal Year: 2021, Volume and Issue: 121(20), P. 12784 - 12965

Published: Aug. 27, 2021

This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, 12–16. Particular attention will be given emerging use said rapidly expanding field Main Group element-mediated catalysis. While this is comprehensive nature, focus research appearing open literature since 2001.

Language: Английский

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A Strategy for Selective Catalytic B–H Functionalization of o-Carboranes

Accounts of Chemical Research, Journal Year: 2021, Volume and Issue: 54(21), P. 4065 - 4079

Published: Oct. 24, 2021

ConspectusCarboranes are a class of polyhedral carbon-boron molecular clusters featuring three-dimensional aromaticity, which often considered as 3D analogues benzene. Their unique structural and electronic properties make them invaluable building blocks for applications ranging from functional materials to versatile ligands pharmaceuticals. Thus, selective functionalization carboranes has received tremendous research interest. In earlier days, the vast majority works in this area were focused on cage carbon via facile deprotonation CH, followed by reaction with electrophiles. On contrary, B-H activation is very challenging since 10 bonds o-carborane similar, how achieve desired transformation at specific boron vertex long-standing issue.As more electronegative than boron, property results different charges cage, follow order B(3,6)-H ≪ B(4,5,7,11)-H < B(8,10)-H B(9,12)-H. We thought that difference may trigger favorite interaction proper transition metal complex bond carborane, could be utilized solve selectivity issue. Accordingly, our strategy described follows: (1) electron-rich catalysts good most electron-deficient (connected both C-H vertices); (2) relatively B(8,9,10,12)-H (with no bonding either (3) directing-group-assisted catalysis appropriate only one vertex), whose lie middle range bonds. This been successfully applied laboratory other groups development series synthetic routes catalytic carborane resulting synthesis large number cage-boron-functionalized derivatives regioselective fashion. Subsequently, significant progress emerging made.In 2013 we reported tetrafluorination o-carboranes using an Pd(II) salt, [Pd(MeCN)4][BF4], catalyst. 2014 disclosed first example carboxy-directed alkenylation B(4) promoted Ir(III) 2017 presented Ir(I)-catalyzed diborylation also uncovered Pd-catalyzed asymmetric chiral-at-cage 2018. These proof-of-principle studies have greatly stimulated activities enabled catalysts. so far developed toolbox methods B-olefination, -arylation, -alkenylation, -alkynylation, -oxygenation, -sulfenylation, -borylation, -halogenation, -amination. recently expanded base catalysis. As field progresses, expect will invented, detailed Account promote these efforts.

Language: Английский

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Carboranes as unique pharmacophores in antitumor medicinal chemistry

Molecular Therapy — Oncolytics, Journal Year: 2022, Volume and Issue: 24, P. 400 - 416

Published: Jan. 10, 2022

Carborane is a carbon-boron molecular cluster that can be viewed as 3D analog of benzene. It features special physical and chemical properties, thus has the potential to serve new type pharmacophore for drug design discovery. Based on relative positions two cage carbons, icosahedral closo-carboranes classified into three isomers, ortho-carborane (o-carborane, 1,2-C2B10H12), meta-carborane (m-carborane, 1,7-C2B10H12), para-carborane (p-carborane, 1,12-C2B10H12), all them deboronated generate their nido- forms. Cage compound carborane its derivatives have been demonstrated useful entities in antitumor medicinal chemistry. The applications carboranes field research mainly include boron neutron capture therapy (BNCT), BNCT/photodynamic dual sensitizers, anticancer ligands. This review summarizes progress achieved up October 2021, with particular emphasis signaling transduction pathways, structures, mechanistic considerations using carboranes.

Language: Английский

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o-Carborane-Based and Atomically Precise Metal Clusters as Hypergolic Materials

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(28), P. 12010 - 12014

Published: June 25, 2020

Atomically precise o-carboranealkynyl-protected clusters [Ag14(C4B10H11)12(CH3CN)2]·2NO3 (CBA-Ag) and [Cu6Ag8(C4B10H11)12Cl]NO3 (CBA-CuAg) have been found to exhibit hypergolic activity, such that they are capable of spontaneous ignition combustion upon contact with the white fuming nitric acid oxidizer. In particular, CBA-CuAg has a short delay time 15 ms, whereas o-carboranealkynyl ligand is hypergolically inert. Systematic investigation revealed metal cluster core catalyzed behavior inert ligand, Cu doping further accelerated catalysis. This work provides new prospective in rational design novel cluster-based fuels for propellant application.

Language: Английский

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Recent Advances in Transition Metal-Catalyzed Selective B-H Functionalization ofo-Carboranes

Bulletin of the Chemical Society of Japan, Journal Year: 2020, Volume and Issue: 94(3), P. 879 - 899

Published: Dec. 18, 2020

Abstract Carboranes are a class of carbon-boron molecular clusters, possessing extraordinary characteristics including three-dimensional aromaticity conjugated by σ-bonds, icosahedral geometry and inherent robustness. They finding growing applications as valuable building blocks in boron neutron capture therapy agents, pharmacophores, nanomaterials, optoelectronic, organometallic/coordination chemistry more. Therefore, the effective controlled functionalization carboranes has attracted enormous research interests, particularly regio- enantio-selective cage BH derivatization among ten chemically similar vertices o-carboranes. Only recent few years, significant progress been made transition metal catalyzed vertex-specific functionalization. This review summarizes advances this realm.

Language: Английский

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B(9)-OH-o-Carboranes: Synthesis, Mechanism, and Property Exploration

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(13), P. 7331 - 7342

Published: March 24, 2023

Herein, we present a chemically robust and efficient synthesis route for B(9)-OH-o-carboranes by the oxidation of o-carboranes with commercially available 68% HNO3 under assistance trifluoromethanesulfonic acid (HOTf) hexafluoroisopropanol (HFIP). The reaction is highly wide scope carboranes, selectivity B(9)/B(8) up to 98:2. success this transformation relies on strong electrophilicity oxidizability HNO3, promoted through hydrogen bonds Brønsted HOTf solvent HFIP. Mechanism studies reveal that o-carborane involves an initial electrophilic attack atom at most electronegative B(9) o-carborane. In transformation, B-H bond nucleophilic site, which different from substitution reaction, where boron site. Therefore, oxidation-reduction mild conditions in N(V) → N(III) H(-I) H(I). derivatization 9-OH-o-carborane was further examined, carboranyl group successfully introduced amino acid, polyethylene glycol, biotin, deoxyuridine, saccharide. Undoubtedly, approach provides selective way rapid incorporation carborane moieties into small molecules application neutron capture therapy, requires targeted delivery boron-rich groups.

Language: Английский

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Aromatic halogenation using carborane catalyst

Chem, Journal Year: 2023, Volume and Issue: 10(1), P. 402 - 413

Published: Nov. 6, 2023

Language: Английский

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Chemistry of three-dimensional icosahedral boron clusters anions: closo-dodecaborate (2-) [B12H12]2- and carba-closo-dodecaborate(-) [CB11H12]-

Coordination Chemistry Reviews, Journal Year: 2024, Volume and Issue: 516, P. 215974 - 215974

Published: June 8, 2024

Language: Английский

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Catalytic Cascade Dehydrogenative Cross-Coupling of BH/CH and BH/NH: One-Pot Process to Carborano-Isoquinolinone

Journal of the American Chemical Society, Journal Year: 2019, Volume and Issue: 141(32), P. 12855 - 12862

Published: July 15, 2019

A proof-of-principle study of cascade dehydrogenative cross-coupling carboranyl carboxylic acid with readily available benzamide has been achieved, resulting in the facile synthesis previously inaccessible carborano-isoquinolinone derivatives a simple one-pot process, which two cage B-H, one aryl C-H, and N-H bond were sequentially activated to construct efficiently new B-C B-N bonds, respectively. Under suitable reaction conditions, such cyclization can be stopped at first B-H/C-H step give series α-carboranyl benzamides, suggesting preferential occurrence over that B-N. The directing group plays key role step, is then removed through situ decarboxylation. CV results combined control experiments indicate high-valent Ir(V)-species may involved pathways, crucial for reactions. isolation structural identification intermediate, its controlled transformations, deuterium labeling support Ir-nitrene-mediated amination B-H/N-H dehydrocoupling.

Language: Английский

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