John Bacsa
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View article: Single-Determinant Ground State in Ce <sup>4+</sup> Imidophosphorane Complexes
Single-Determinant Ground State in Ce <sup>4+</sup> Imidophosphorane Complexes Open
X-ray spectroscopy techniques are critical in the electronic structure analysis of high-valent lanthanides. The interpretation of multipeaked features at the lanthanide L3-edge has remained a challenging question, as it is observed across …
View article: Testing the Luedemann hypothesis: the discovery of novel antimicrobials from slow-growing microbes from nutrient-limited environments
Testing the Luedemann hypothesis: the discovery of novel antimicrobials from slow-growing microbes from nutrient-limited environments Open
George Luedemann is known throughout the antimicrobial community as one of the discoverers of the natural product antibiotic gentamicin. He subsequently hypothesized that slow-growing organisms inhabiting inhospitable, nutrient-limited env…
View article: Total Synthesis of (−)-Neocucurbol C Enabled by Pattern Recognition and MHAT Cyclization
Total Synthesis of (−)-Neocucurbol C Enabled by Pattern Recognition and MHAT Cyclization Open
We report an asymmetric total synthesis of (-)-neocucurbol C, a diterpene natural product possessing a unique and complex 6/6/5/5/6 polycyclic skeleton and nine stereocenters. Pattern-recognition analysis led us to the chiral pool molecule…
View article: Asymmetric C–H Functionalization of <i>N</i>-Boc-2,5-dihydro-1<i>H</i>-pyrrole and Its Application as a Key Step in the Synthesis of (−)-Dragocin D
Asymmetric C–H Functionalization of <i>N</i>-Boc-2,5-dihydro-1<i>H</i>-pyrrole and Its Application as a Key Step in the Synthesis of (−)-Dragocin D Open
Dirhodium tetracarboxylate-catalyzed reaction of aryldiazoacetates with N-Boc-2,5-dihydro-1H-pyrrole results in a highly enantio- and diastereoselective C-H functionalization exclusively at the α-N C2 position. This result is a sharp contr…
View article: Development of a Diastereoselective Csp<sup>2</sup>–Csp<sup>3</sup> Cross-Coupling Reaction Inspired by Macrocyclic RiPP Natural Products
Development of a Diastereoselective Csp<sup>2</sup>–Csp<sup>3</sup> Cross-Coupling Reaction Inspired by Macrocyclic RiPP Natural Products Open
Macrocyclic peptides containing C(sp2)-C(sp3) side chain cross-links are a rapidly growing subclass of ribosomally synthesized and post-translationally modified peptides (RiPPs), with significant potential in the development of new pharmac…
View article: Enantioselective 3,4-Oxyamination of 1,3-Dienes Enabled by an Electron-Rich Planar Chiral Rhodium Indenyl Catalyst
Enantioselective 3,4-Oxyamination of 1,3-Dienes Enabled by an Electron-Rich Planar Chiral Rhodium Indenyl Catalyst Open
We describe the development of a three-component enantioselective 3,4-amino oxygenation protocol for 1,3-dienes enabled by a highly methylated electron-rich planar chiral rhodium indenyl catalyst. This transformation furnishes vicinal amin…
View article: Impact of Induced Fitting and Secondary Noncovalent Interactions on Site-Selective and Enantioselective C–H Functionalization of Arylcyclohexanes
Impact of Induced Fitting and Secondary Noncovalent Interactions on Site-Selective and Enantioselective C–H Functionalization of Arylcyclohexanes Open
A major challenge in organic synthesis is the selective functionalization of C-H bonds. As most organic compounds contain multiple C-H bonds with similar properties, distinguishing between them requires precise control. In this study, we s…
View article: Evidence for Bose liquid from anomalous shot noise in nanojunctions of bad metal beta-Ta
Evidence for Bose liquid from anomalous shot noise in nanojunctions of bad metal beta-Ta Open
We report anomalous shot noise in nanojunctions of beta-tantalum, a ``bad" metal whose electronic properties are inconsistent with the Fermi liquid theory. Fano factors cluster around even multiples of the values expected for Fermi liquids…
View article: Redox-Active Ligands Permit Multielectron O<sub>2</sub> Homolysis and O-Atom Transfer at Exceptionally High-Valent Vanadyl Complexes
Redox-Active Ligands Permit Multielectron O<sub>2</sub> Homolysis and O-Atom Transfer at Exceptionally High-Valent Vanadyl Complexes Open
A five-coordinate chlorovanadium species supported by two redox-active N-phenyl aminophenol ligands was prepared. Experimental and computational data support formulation of this complex as [(Phap)(Phisq)VIVCl], containing one dianionic [Ph…
View article: <i>C</i><sub>4</sub>-Symmetric Bowl-Shaped Diruthenium Tetracarboxylate Catalysts for Enantioselective C–H Functionalization Using Donor/Acceptor Carbenes
<i>C</i><sub>4</sub>-Symmetric Bowl-Shaped Diruthenium Tetracarboxylate Catalysts for Enantioselective C–H Functionalization Using Donor/Acceptor Carbenes Open
Cationic diruthenium (II,III) tetracarboxylate catalysts have been shown to catalyze selective intermolecular C-H functionalization reactions using donor/acceptor carbenes in high yield and with high levels of enantioselectivity. The dirut…
View article: Reversible C–CN Bond Cleavage by a Formal Dinickel(I) Hydride Cation
Reversible C–CN Bond Cleavage by a Formal Dinickel(I) Hydride Cation Open
An N-heterocyclic carbene (NHC) ligand supports a stable [Ni2H]+ core, formally dinickel(I). This diamagnetic cation complex features a bent hydride bridge and a Ni···Ni distance, 2.9926(5) Å, larger than two covalent radii. The cation dis…
View article: Anomalous shot noise in a bad metal beta-tantalum
Anomalous shot noise in a bad metal beta-tantalum Open
We investigate the electronic shot noise produced by nanowires of $β$-Ta, an archetypal ``bad" metal with resistivity near the Ioffe-Regel localization limit. The Fano factor characterizing the shot noise exhibits a strong dependence on te…
View article: Decarboxylative Cross-Coupling Enabled by Fe and Ni Metallaphotoredox Catalysis
Decarboxylative Cross-Coupling Enabled by Fe and Ni Metallaphotoredox Catalysis Open
Decarboxylative cross-coupling of carboxylic acids and aryl halides has become a key transformation in organic synthesis to form C(sp2)-C(sp3) bonds. In this report, a base metal pairing between Fe and Ni has been developed with complement…
View article: N‐Halogenation by Vanadium‐Dependent Haloperoxidases Enables 1,2,4‐Oxadiazole Synthesis
N‐Halogenation by Vanadium‐Dependent Haloperoxidases Enables 1,2,4‐Oxadiazole Synthesis Open
Nitrogen‐containing compounds are valuable synthetic intermediates and targets in nearly every chemical industry. While methods for nitrogen‐carbon and nitrogen‐heteroatom bond formation have primarily relied on nucleophilic nitrogen atom …
View article: N‐Halogenation by Vanadium‐Dependent Haloperoxidases Enables 1,2,4‐Oxadiazole Synthesis
N‐Halogenation by Vanadium‐Dependent Haloperoxidases Enables 1,2,4‐Oxadiazole Synthesis Open
Nitrogen‐containing compounds are valuable synthetic intermediates and targets in nearly every chemical industry. While methods for nitrogen‐carbon and nitrogen‐heteroatom bond formation have primarily relied on nucleophilic nitrogen atom …
View article: Halide Abstraction-Mediated Synthesis of a Highly Twisted Amide
Halide Abstraction-Mediated Synthesis of a Highly Twisted Amide Open
[Image: see text] Highly strained [3.2.1] bicyclic twisted amide 2 and corresponding amidium 10 were synthesized for the first time through Ag(I)-mediated halide abstraction. After initial lactamization attempts failed, a second-generation…
View article: D<sub>4</sub>-Symmetric Dirhodium Tetrakis(binaphthylphosphate) Catalysts for Enantioselective Functionalization of Unactivated C–H Bonds
D<sub>4</sub>-Symmetric Dirhodium Tetrakis(binaphthylphosphate) Catalysts for Enantioselective Functionalization of Unactivated C–H Bonds Open
Dirhodium tetrakis(2,2'-binaphthylphosphate) catalysts were successfully developed for asymmetric C-H functionalization with trichloroethyl aryldiazoacetates as the carbene precursors. The 2,2'-binaphthylphosphate (BNP) ligands were modifi…
View article: Decarboxylative Cross-Coupling Enabled by Fe and Ni Metallaphotoredox Catalysis
Decarboxylative Cross-Coupling Enabled by Fe and Ni Metallaphotoredox Catalysis Open
Decarboxylative cross-coupling of carboxylic acids and aryl halides has become a key transformation in organic synthe- sis to form C(sp2)–C(sp3) bonds. In this report, a base metal pairing between Fe and Ni has been developed with compleme…
View article: Michael Addition–Elimination Ring-Opening Polymerization
Michael Addition–Elimination Ring-Opening Polymerization Open
A cyclic thioenone system capable of controlled ring-opening polymerization (ROP) is presented that leverages a reversible Michael addition-elimination (MAE) mechanism. The cyclic thioenone monomers are easy to access and modify and for th…
View article: Biocatalytic N-Halogenation Enabled by Vanadium-Dependent Haloperoxidases
Biocatalytic N-Halogenation Enabled by Vanadium-Dependent Haloperoxidases Open
Nitrogen-containing compounds are valuable synthetic intermediates and targets in nearly every chemical industry. While methods for nitrogen-carbon and nitrogen-heteroatom bond formation have primarily relied on nucleophilic nitrogen atom …
View article: Investigating the Effect of Trace Levels of Manganese Ions During Solvothermal Synthesis of Massey University Framework-16 on CO<sub>2</sub> Uptake Capacity
Investigating the Effect of Trace Levels of Manganese Ions During Solvothermal Synthesis of Massey University Framework-16 on CO<sub>2</sub> Uptake Capacity Open
The effects of impurities on reaction precursors for metal-organic framework (MOF) synthesis have not been studied in extensive detail. The impact of these impurities can be an important factor while considering scale-up of these materials…
View article: Rhodium(II)-Catalyzed Asymmetric Cyclopropanation and Desymmetrization of [2.2]Paracyclophanes
Rhodium(II)-Catalyzed Asymmetric Cyclopropanation and Desymmetrization of [2.2]Paracyclophanes Open
Chiral [2.2]paracyclophane derivatives are of considerable interest because of their potential in asymmetric catalysis and the development of chiral materials. This study describes the scope of rhodium-catalyzed reactions of aryldiazoaceta…
View article: Intervalence Charge Transfer in Nonbonding, Mixed-Valence, Homobimetallic Ytterbium Complexes
Intervalence Charge Transfer in Nonbonding, Mixed-Valence, Homobimetallic Ytterbium Complexes Open
There are several reports of compounds containing lanthanide ions in two different formal oxidation states; however, there are strikingly few examples of intervalence charge transfer (IVCT) transitions observed for these complexes, with th…
View article: Convergent and Efficient Total Synthesis of (+)-Heilonine Enabled by C–H Functionalizations
Convergent and Efficient Total Synthesis of (+)-Heilonine Enabled by C–H Functionalizations Open
We report a convergent and efficient total synthesis of the C-nor D-homo steroidal alkaloid (+)-heilonine with a hexacyclic ring system, nine stereocenters, and a trans-hydrindane moiety. Our synthesis features four selective C-H functiona…
View article: Stereoelectronic interactions are too weak to explain the molecular conformation in solid state of <i>cis</i>-2-<i>tert</i>-butyl-5-(<i>tert</i>-butylsulfonyl)-1,3-dioxane
Stereoelectronic interactions are too weak to explain the molecular conformation in solid state of <i>cis</i>-2-<i>tert</i>-butyl-5-(<i>tert</i>-butylsulfonyl)-1,3-dioxane Open
In the solid state, cis -1 exhibits a high degree of eclipsing in the H–C5–S–C segment. The rigorous study of the experimental electro density allowed to establish that CH⋯OS intermolecular interaction is the main contribution to the obser…
View article: Color Control in Bis-ethylenedioxythiophene Phenylene Anodically Coloring Electrochromes
Color Control in Bis-ethylenedioxythiophene Phenylene Anodically Coloring Electrochromes Open
This work assesses the steric, torsional, and electronic effects of substituents on anodically coloring electrochromic (ACE) molecules to gain insight toward constructing highly transmissive neutral states, while attaining vibrant colors i…
View article: Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity
Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity Open
1,3-Dimethyl-2,3-dihydrobenzo[ d ]imidazoles, 1H , and 1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[ d ]imidazoles, 1 2 , are of interest as n-dopants for organic electron-transport materials. Salts of 2-(4-(dimethylamino)phenyl…