Rapid Synthesis of Primary Amides Using Ammonia Borane

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: 90(4), P. 1720 - 1726

Published: Jan. 23, 2025

We report the rapid synthesis of primary amides by directly using commercially available ammonia borane (NH3·BH3), sodium hexamethyldisilazide (NaHMDS), and esters. The success this protocol relies on NH3·BH3 as nitrogen source being considerably more convenient NaHMDS an excellent proton abstractor but not participating in nucleophilic addition reaction. reaction had a wide substrate scope containing bioactive molecules, most substrates were efficiently amidated over 90% yields.

Language: Английский

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Palladium-Catalyzed Cross-Coupling Reactions of Carboranes with Alkenes via Selective B–H Bond Activation

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

A palladium-catalyzed Heck-type cross-coupling reaction of carboranes with alkenes in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) was realized. This shows good B(9) selectivity for m-carboranes and is also suitable o- p-carborane. Meanwhile, a series mono-, di-, trisubstituted were compatible substrates to afford the alkenylated products 16–89% yields. The 1,2-bis(carboranyl)ethylene first synthesized by vinyltrimethylsilane m-carborane. Further transformations C═C bond product examined hydroboration oxidation, hydroboration, bromination generate corresponding B(9)-functionalized m-carboranes.

Language: Английский

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Chelating 1,2-Bis(2′-picolyl)-o-carborane as a Supporting Ligand for Pd-Catalyzed Selective B(3,6)–H Difunctionalization of o-Carboranes

Inorganic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

Transition metal catalyzed selective cage B–H functionalization of carboranes has made significant progress in recent years, giving rise to the efficient synthesis a large variety B-functionalized including alkenylation, arylation, alkynylation, borylation, hydroxylation, acyloxylation, amination, and halogenation. However, mechanisms these catalytic B–X coupling reactions are not well understood. Herein, we describe isolation characterization catalytically relevant o-carborane based palladium(II) metallacycle, disclosing details Pd-catalyzed o-carboranes. As result, highly B(3,6)-dihalogenation, -dimethylation, -diarylation o-carboranes have been achieved.

Language: Английский

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Taming Inert B–H Bond with Low Energy Light: A Near-Infrared Light-Induced Approach to Facile Carborane Cluster-Amino Acid Coupling

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 1, 2025

The selective functionalization of inert B–H bonds in carborane clusters has been a formidable challenge. Recent advances have witnessed such reactions through photoredox methods utilizing ultraviolet or visible light irradiation. However, high-energy sources often suffer from poor energy efficiency, limited substrate scope, undesired side reactions, and low scalability. Here, we present the first successful bond under low-energy near-infrared (NIR) using carborane-based electron donor–acceptor complex. Both photophysical investigations theoretical modeling reveal facile single-electron transfer cage to electron-deficient photocatalyst, generating radical NIR follow-up pathway enables direct coupling carboranes with amino acids oligopeptides, yielding diverse array carborane-functionalized oligopeptides. Beyond expanding known chemical space boron cluster derivatives, further demonstrate that imaging targeting capabilities could serve as promising multifunctional carriers for neutron capture therapy. Thus, via not only provides straightforward practical strategy synthetic chemistry but also lays foundation development next-generation boron-containing biomolecules advanced functional materials.

Language: Английский

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Polyoxometalate-Supported Pd(II)-Catalyzed B(9)–H Nitration of o/m-Carboranes

ACS Catalysis, Journal Year: 2025, Volume and Issue: unknown, P. 7646 - 7652

Published: April 23, 2025

Language: Английский

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Post-coordination of Ru(II) Controlled Regioselective B(4)–H Acylmethylation of o-Carboranes with Sulfoxonium Ylides

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Despite significant progress in the B-H functionalization of carboranes, development cost-effective catalytic systems devoid noble metals, coupled with mechanistic validation regioselectivity control, remains a formidable challenge. Herein, we disclose an Ag salt-free, redox-neutral, and inexpensive ruthenium(ii)-catalyzed protocol that enables exclusive B(4)-H acylmethylation o-carboranes through novel post-coordination strategy. By exploiting weakly coordinating carboxylic acid as traceless directing group, this method achieves excellent mono-site selectivity for B-C(sp3) bond formation using diverse sulfoxonium ylides, demonstrating both functional group tolerance synthetic scalability. This work not only establishes practical platform but also addresses critical questions unresolved prior analogous studies. Through deuterium labeling, situ high-resolution mass spectrometry (HRMS) tracking, single-crystal X-ray analysis Ru intermediates, unequivocally demonstrate originates from unique mode Ru(ii). The catalyst simultaneously engages enolizable acylmethyl moiety mono-acylated intermediate, thereby dictating activation trajectory. Our findings establish generalizable regiocontrolled carborane while defining paradigms transition metal-mediated chemistry.

Language: Английский

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Reaction of Carboranyl Lithium and 2,3-Dichloroquinoxaline to Synthesize Carborane-Fused N-Heteroaromatic

Organometallics, Journal Year: 2024, Volume and Issue: 43(10), P. 1077 - 1084

Published: May 16, 2024

Nucleophilic substitution of B–H is an important strategy for the synthesis carborane derivatives. Although intermolecular nucleophilic has been widely explored, intramolecular rarely reported. Herein, we synthesized a novel carborane-fused N-heteroaromatic through transition-metal-free reaction between carboranyl lithium and 2,3-dichloroquinoxaline. Two C–Cl substitutions one with were involved in this transformation. Instead most electron-deficient B(3)–H vertex, selectively occurred on B(4)–H vertex. This method provides new ring compounds.

Language: Английский

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Couple-close construction of non-classical boron cluster-phosphonium conjugates

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Sept. 11, 2024

Language: Английский

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A variable bidentate traceless directing group for nickel-catalyzed regioselective B–H poly-chalcogenation of o-carboranes

Inorganic Chemistry Frontiers, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A nickel-catalyzed direct cage B–H poly-chalcogenation of icosahedral carborane clusters, enabled by a variable bidentate 8-aminoquinoline traceless directing group, has been developed under oxidant-free and weakly basic conditions.

Language: Английский

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Highly selective electrophilic B(9)-amination of o-carborane driven by HOTf and HFIP

Organic Chemistry Frontiers, Journal Year: 2022, Volume and Issue: 9(18), P. 4975 - 4980

Published: Jan. 1, 2022

An efficient B(9) electrophilic amination of o -carboranes with azodicarboxylates, promoted by a Brønsted acid and HFIP, was developed.

Language: Английский

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