Assessing the donor ability of boratabenzene and 9-borataphenanthrene anions through metal complexes with carbonyl ligands

Rojales, Katherine; Tamizmani, Masilamani; Bartholome, Tyler A.; Martin, Caleb D.

doi:10.1039/d2dt02795j

Cited by 3 publications

(2 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are reports of BN-phenanthrenes, boroxophenanthrene, and our laboratory reported a neutral BP-phenanthryne through photolysis of a boraphosphaketene . Martin and co-workers isolated the first 9-borataphenanthrene anion and explored its reactivity . We noted that the neutral and radical forms of boraphenanthrene had not been reported but would provide useful building blocks for more complex benzene-rich molecular scaffolds that contain boron.…”

Section: Reduced 6-membered Boracycles: Boraphenanthrenes and Boraphe...mentioning

confidence: 92%

Redox- and Charge-State Dependent Trends in 5, 6, and 7-Membered Boron Heterocycles: A Neutral Ligand Coordination Chemistry Approach to Boracyclic Cations, Anions, and Radicals

Hollister,

Wentz,

Gilliard

2024

Acc. Chem. Res.

View full text Add to dashboard Cite

Metrics & MoreArticle Recommendations CONSPECTUS: Boron heterocycles represent an important subset of heteroatom-incorporated rings, attracting attention from organic, inorganic, and materials chemists. The empty p z orbital at the boron center makes them stand out as quintessential Lewis acidic molecules, also serving as a means to modulate electronic structure and photophysical properties in a facile manner. As boracycles are ripe for extensive functionalization, they are used in catalysis, chemical biology, materials science, and continue to be explored as chemical synthons for conjugated materials and reagents.Neutral boron(III)-incorporated polycyclic molecules are some of the most studied types of boracycles, and understanding their redox transformations is important for applications relying on electron transfer and charge transport. While relevant redox species can often be electrochemically observed, it remains challenging to isolate and characterize boracycles where the boron center and/or polycyclic skeleton have been chemically reduced. We describe our recent work isolating 5-, 6-, and 7-membered boracyclic radicals, anions, and cations, focusing on stabilization strategies, ligand-mediated bonding situations, and reactivity. We present a versatile neutral ligand coordination chemistry approach that permits the transformation of boracycles from potent electrophiles to powerful nucleophilic heterocycles that facilitate diverse electron transfer and bond activation chemistry. Although there are a wide range of suitable stabilizing ligands, we have employed both diamino-N-heterocyclic carbenes (NHCs) and cyclic(alkyl)(amino) carbenes (CAACs), which led to boracycles with tunable electronic structures and aromaticity trends. We highlight successful isolation of borafluorene radicals and demonstrate their reversible redox behavior, undergoing oxidation to the cation or reduction to the anion. The borafluorene anion is a chemical synthon that has been used to prepare boryl main-group and transition-metal bonds, luminescent oxabora-spirocycles, borafluorenate-crown ethers, and CO-releasing molecules via carbon dioxide activation. We expanded to 6-membered boracycles and characterized neutral bis(NHC-supported 9-boraphenanthrene)s and the corresponding bis(CAAC-stabilized 9-boraphenanthrene) biradical. We detail the interconvertible multiredox states of boraphenalene, where the boraphenalenyl radical, anion, and cation mimic the charge-states of the all-hydrocarbon analogue. Reactivity studies of the boraphenalenyl anion displayed unusual nucleophilic reactivity at multiple sites on the periphery of the boraphenalenyl tricyclic scaffold. Reduced borepins, 7-membered boron containing heterocycles, have also been isolated. We used a stepwise one-pot synthesis combining the halo-borepin precursor, CAAC, and KC 8 to afford the monomeric borepin radicals and anions. The π-system was extended to contain two borepin rings fused in a pentacyclic scaffold, which permitted isolation of diborepin biradicals and a diborep...

show abstract

Section: Reduced 6-membered Boracycles: Boraphenanthrenes and Boraphe...mentioning

confidence: 92%

Redox- and Charge-State Dependent Trends in 5, 6, and 7-Membered Boron Heterocycles: A Neutral Ligand Coordination Chemistry Approach to Boracyclic Cations, Anions, and Radicals

Hollister,

Wentz,

Gilliard

2024

Acc. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…The examples 16 and 17 , in contrast, were prepared in a more convenient way, namely by the reaction of the respective borataalkene anion with the metal halides. 11,12…”

Section: The Borataalkenesmentioning

confidence: 99%

The BC bond: some recent developments

2023

View full text Add to dashboard Cite

show abstract

Triple-Decker Iron and Cobalt Complexes Featuring a Bridging 1,2-Diboratabenzene Ligand

Tamizmani

Tidwell

Reinheimer³

et al. 2023

Inorg. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

Assessing the donor ability of boratabenzene and 9-borataphenanthrene anions through metal complexes with carbonyl ligands

Abstract: A series of anionic group 6 tricarbonyl and neutral rhodium dicarbonyl complexes featuring a boratabenzene (L1, with a phenyl on boron, a trimethylsilyl group on the adjacent carbon and methyl...

Cited by 3 publications

References 57 publications

Redox- and Charge-State Dependent Trends in 5, 6, and 7-Membered Boron Heterocycles: A Neutral Ligand Coordination Chemistry Approach to Boracyclic Cations, Anions, and Radicals

Redox- and Charge-State Dependent Trends in 5, 6, and 7-Membered Boron Heterocycles: A Neutral Ligand Coordination Chemistry Approach to Boracyclic Cations, Anions, and Radicals

The BC bond: some recent developments

Triple-Decker Iron and Cobalt Complexes Featuring a Bridging 1,2-Diboratabenzene Ligand

Contact Info

Product

Resources

About