Cited by Pd-Catalyzed Oxidative Dehydrogenative Cross Coupling of Cage B–H/B–H Bonds at Room Temperature: Synthesis of Bis(<i>o</i>-carborane)s

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

Zaozao Qiu, Zuowei Xie

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

Citations

110

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

Yik Ki Au, Zuowei Xie

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

Citations

Copper-Catalyzed Electrochemical Selective B–H Oxygenation of o-Carboranes at Room Temperature DOI

Yik Ki Au, Hairong Lyu, Yangjian Quan

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(15), P. 6940 - 6945

Published: March 31, 2020

Copper-catalyzed electrochemical selective cage B–H oxygenation of o-carboranes has been achieved for the first time. Under a constant electric current (4.0 mA) at room temperature, copper-catalyzed cross-coupling carboranyl amides with lithium phenolates results in formation B(4,5)-diphenolated via direct activation, whereas use tert-butoxide affords B(4)-monooxygenated products. This reaction does not require any additional chemical oxidants and generates H2 salt as byproducts. Control experiments indicated that high-valent Cu(III) species is likely involved process.

Language: Английский

Citations

Regioselective B(3,4)–H arylation of o-carboranes by weak amide coordination at room temperature DOI

Yu‐Feng Liang, Long Yang,

Becky Bongsuiru Jei

et al.

Chemical Science, Journal Year: 2020, Volume and Issue: 11(39), P. 10764 - 10769

Published: Jan. 1, 2020

B–H: site-selective B(3,4)–H arylations were accomplished at room temperature by versatile palladium catalysis enabled weakly coordinating amides.

Language: Английский

Citations

Functional Group Directed B–H Activation of Polyhedral Boron Hydrides by Transition Metal Complexes (Review) DOI

Igor B. Sivaev

Russian Journal of Inorganic Chemistry, Journal Year: 2021, Volume and Issue: 66(9), P. 1289 - 1342

Published: Sept. 1, 2021

Language: Английский

Citations

Ir-Catalyzed Selective B(3)-H Amination of o-Carboranes with NH₃ DOI

Yik Ki Au, Jie Zhang, Yangjian Quan

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(11), P. 4148 - 4153

Published: March 15, 2021

Ammonia gas, NH3, is a cheap and widely used industrial feedstock, which has received tremendous research interests in its functionalization. This work reports breakthrough catalytic selective cage B(3)-H amination of o-carboranes with NH3 via Ir-catalyzed B-H/N-H dehydrocoupling, offering convenient efficient access to series 3-NH2-o-carborane derivatives moderate high isolated yields broad substrate scope. The employment readily available gas as the aminating reagent H2 sole byproduct endows protocol economy, practicability, environmental friendliness. A plausible reaction mechanism proposed on basis control experiments.

Language: Английский

Citations

Electrochemical Cage Activation of Carboranes DOI

Long Yang, Zijing Zhang,

Becky Bongsuiru Jei

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(20)

Published: Feb. 11, 2022

Abstract Carboranes are boron–carbon molecular clusters that possess unique properties, such as their icosahedron geometry, high boron content, and delocalized three‐dimensional aromaticity. These features render carboranes valuable building blocks for applications in supramolecular design, nanomaterials, optoelectronics, organometallic coordination chemistry, neutron capture therapy (BNCT) agents. Despite tremendous progress this field, stoichiometric chemical redox reagents largely required the oxidative activation of carborane cages. In context, electrosyntheses represent an alternative strategy more sustainable syntheses. It is only recent few years considerable has been made electrochemical cage functionalization carboranes, which summarized Minireview. We anticipate electrocatalysis will serve increasingly powerful stimulus within current renaissance electrochemistry.

Language: Английский

Citations

Practical Synthesis of B(9)-Halogenated Carboranes with N-Haloamides in Hexafluoroisopropanol DOI

Wenjing Guo,

Chenyang Guo,

Yan‐Na Ma

et al.

Inorganic Chemistry, Journal Year: 2022, Volume and Issue: 61(13), P. 5326 - 5334

Published: March 21, 2022

The B(9)-H halogenation of o-carborane and m-carborane was achieved with excellent selectivities in hexafluoroisopropanol (HFIP) under simple reaction conditions: single reagent [trichloroisocyanuric acid (TCCA), tribromoisocyanuric (TBCA) or N-iodosuccinimide (NIS)], catalyst-free, air-/moisture-tolerant, convenient work-up. With this method, a variety 9-halogenated o-carboranes m-carboranes were obtained good to yields broad tolerance functional groups.

Language: Английский

Citations

Iridium‐Catalyzed Regioselective B(3)‐Alkenylation/B(3,6)‐Dialkenylation of o‐Carboranes by Direct B−H Activation DOI

Ruofei Cheng, Zaozao Qiu, Zuowei Xie

et al.

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(32), P. 7212 - 7218

Published: Feb. 10, 2020

Abstract Iridium‐catalyzed formal alkyne hydroboration with cage B−H of o ‐carborane has been achieved, leading to the controlled synthesis a series 3,6‐[ trans ‐(AlkCH=CH)] 2 ‐ ‐carboranes (Alk=alkyl), 3‐ cis ‐(ArCH=CH)‐ (Ar=aryl), and ‐(ArCH=CH)‐6‐ ‐(AlkCH=CH)‐ in high yields excellent regio‐ very good – selectivity. The most electron‐deficient B(3,6)−H vertices favor oxidative addition on electron‐rich metal centers, which is responsible for regioselectivity. On other hand, configuration resultant olefinic units dominated by substituents. Alkyl groups lead ‐configuration whereas bulky aryl substitutions result ‐configuration.

Language: Английский

Citations

8-Aminoquinoline as a bidentate traceless directing group for Cu-catalyzed selective B(4,5)–H disulfenylation ofo-carboranes DOI

Yu Chen, Yangjian Quan, Zuowei Xie

et al.

Chemical Communications, Journal Year: 2020, Volume and Issue: 56(85), P. 12997 - 13000

Published: Jan. 1, 2020

A traceless bidentate directing group guided copper catalyzed direct cage B(4,5)-H disulfenylation of o-carboranes has been achieved, leading to a series B(4,5)-disulfenylated o-carborane derivatives in high yields with excellent regioselectivity. The situ departure the 8-aminoquinoline auxiliary circumvents additional processes for removal, thus enhancing atom-/step-economy.

Language: Английский

Citations