A5035441621- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Fluorine in Organic Chemistry
- Catalytic Cross-Coupling Reactions
- Catalytic C–H Functionalization Methods
- Metal-Organic Frameworks: Synthesis and Applications
- Covalent Organic Framework Applications
- Cyclopropane Reaction Mechanisms
- Metal complexes synthesis and properties
- Magnetism in coordination complexes
- Luminescence and Fluorescent Materials
- Nanomaterials for catalytic reactions
- CO2 Reduction Techniques and Catalysts
- Organoboron and organosilicon chemistry
- Metal-Catalyzed Oxygenation Mechanisms
- Asymmetric Hydrogenation and Catalysis
- Crystallography and molecular interactions
- Synthesis and Catalytic Reactions
- Synthesis of Indole Derivatives
- Inorganic Fluorides and Related Compounds
- Oxidative Organic Chemistry Reactions
- Genetics, Aging, and Longevity in Model Organisms
- Gender Studies in Language
- Linguistic Variation and Morphology
- Catalysis and Oxidation Reactions
Wayne State University
2022-2025
University of Michigan
2015-2023
Massachusetts Institute of Technology
2020
Hope College
2013
This communication describes the synthesis and reactivity of Ni(IV)(aryl)(CF3)2 complexes supported by trispyrazolylborate 4,4'-di-tert-butylbipyridine ligands. We demonstrate that isolable Ni(IV) can be accessed under mild conditions via oxidation Ni(II) precursors with S-(trifluoromethyl)dibenzothiophenium triflate as well diaryliodonium aryl diazonium reagents. The intermediates undergo high yielding aryl-CF3 bond-forming reductive elimination. These studies support potential viability in...
This manuscript describes the design, synthesis, characterization, and reactivity studies of organometallic NiIII complexes general structure TpNiIII(R)(R1) (Tp = tris(pyrazolyl)borate). With appropriate selection R R1 ligands, are stable at room temperature can be characterized by cyclic voltammetry, EPR spectroscopy, X-ray crystallography. Upon heating, many these compounds undergo C(sp2)–C(sp2) or C(sp3)–C(sp2) bond-forming reactions that challenging lower oxidation states nickel.
This Article describes the development of a base-free, nickel-catalyzed decarbonylative coupling carboxylic acid fluorides with diboron reagents to selectively afford aryl boronate ester products. Detailed studies were conducted assess relative rates direct transmetalation between esters and bisphosphine nickel(aryl)(fluoride) intermediate. These investigations revealed that undergo this Ni(aryl)(fluoride) intermediate at significantly faster than their congeners. Furthermore, reactivity...
This paper describes the one-electron interconversions of isolable NiIII and NiIV complexes through their reactions with carbon-centered radicals (R•). First, model are shown to react alkyl aryl afford products. Preliminary mechanistic studies implicate a pathway involving direct addition radical center. is directly analogous known reactivity NiII R•, step that commonly implicated in catalysis. Second, NiIV–CH3 complex C–C bonds via proposed SH2-type mechanism. leveraged enable challenging...
Nickel K- and L 2,3 -edge X-ray absorption spectra (XAS) are discussed for coordinated nickel centers spanning formal oxidation states from II to IV. The ensuing analysis indicates that a physical “+4” state is untenable Ni.
Difluoromethyl copper complexes have been proposed as key intermediates in a variety of Cu-catalyzed difluoromethylation reactions. However, studies these putative impeded by the low stability [Cu(CHF2)] species. This report describes synthesis isolable N-heterocyclic carbene ligated copper(I) difluoromethyl complexes. The stoichiometric reactions with aryl electrophiles (i.e., diaryliodonium salts, iodides, and bromides) are described. In addition, species demonstrated to serve catalysts...
This Communication describes studies of Ph-RF (RF = CF3 or CF2CF3) coupling at Pd complexes general structure (PtBu3)PdII(Ph)(RF). The analogue participates in fast Ph-CF3 (<5 min 80 °C). However, the formation side products limits yield this transformation as well its translation to catalysis. DFT and experimental suggest that derive from facile α-fluoride elimination 3-coordinate PdII complex. Furthermore, they show undesired pathway can be circumvented by changing a CF2CF3 ligand....
A palladium-catalyzed cross-coupling of aryl chlorides/bromides with TMSCF2H is described. Two different catalysts, Pd(dba)2/BrettPhos and Pd(PtBu3)2, are demonstrated provide a variety difluoromethylated arenes in good yields.
This Article describes the synthesis and characterization of cyclometalated aminoquinoline NiII σ-aryl σ-alkyl complexes that have been proposed as key intermediates in Ni-catalyzed C–H functionalization reactions. These serve competent catalysts for derivatives with I2. They also react stoichiometrically I2 to form either aryl iodides or β-lactams within minutes at room temperature. Furthermore, they AgI salts −30 °C afford isolable five-coordinate NiIII species. The proved inert toward...
An analysis of the palladium-catalyzed activation carbon-carbon single bonds within triarylmethanols has led to a greater understanding factors influencing β-aryl elimination process responsible for C-C bond cleavage. A series competition reactions were utilized determine that aryl substituents containing ortho-substitution proceeds with significant preference unsubstituted phenyl rings. Further experiments indicate substrates either strongly donating or withdrawing are cleaved from more...
This article describes a detailed investigation of ligand effects on Ph–CF3 coupling from phosphinoferrocene-ligated PdII(Ph)(CF3) complexes. study reveals that increasing the size phosphine substituents results in an enhanced rate coupling, with (DtBPF)Pd(Ph)(CF3) (DtBPF = 1,1′-bis(di-tert-butylphosphino)ferrocene) being most reactive complex. The mechanism bond formation both and (DiPrPF)Pd(Ph)(CF3) (DiPrPF 1,1′-bis(diisopropylphosphino)ferrocene) was interrogated experimentally...
Porous aromatic framework (PAF) microporosity is known to be strongly dependent on synthetic approach but little about why certain reactions yield significantly and consistently more porous PAFs. This article explores the connections between pathway, PAF defectivity, microporosity. Using a network disassembly strategy, we show that defectivity highly defective PAFs are associated with lower surface areas pore volumes. empirical association corroborated through systematic introduction of...
Inhaled nitric oxide (iNO) is a promising therapy for variety of pulmonary conditions but limited by the cost, portability, and safety limitations compressed gas cylinders used in conventional iNO delivery systems. On‐demand generation via thermally controlled decomposition an NO‐genic precursor attractive alternative to systems based on cylinders. However, most NO‐releasing materials, which would form basis such system, are designed vivo applications, not flow release at elevated...
Inhaled nitric oxide (iNO) is a promising therapy for variety of pulmonary conditions but limited by the cost, portability, and safety limitations compressed gas cylinders used in conventional iNO delivery systems. On‐demand generation via thermally controlled decomposition an NO‐genic precursor attractive alternative to systems based on cylinders. However, most NO‐releasing materials, which would form basis such system, are designed vivo applications, not flow release at elevated...
This communication describes the synthesis of a series diphosphine NiII(Ph)(CF3) complexes and studies their reactivity toward oxidatively induced Ph–CF3 bond-forming reductive elimination. Treatment these with one-electron outer-sphere oxidant ferrocenium hexafluorophosphate (FcPF6) affords benzotrifluoride, but yield varies dramatically as function ligand. Diphosphines bite angles less than 92° afforded <10% PhCF3. In contrast, those between 95 102° formed PhCF3 in yields ranging from 62 to 77%.
Porous aromatic frameworks (PAFs) are attractive materials for applications where high surface area and material stability govern performance. Most of the highest PAFs synthesized using poorly scalable costly methods involving super-stoichiometric bis(1,5-cyclooctadiene)Nickel(0) (Ni(COD)2). This communication describes a general approach synthesis that does not use isolated Ni(COD)2. The method is to at least seven microporous polymers can be conducted on gram scales without an inert...
Porous aromatic framework microporosity is known to be strongly dependent on synthetic approach, but little about why certain reactions consistently yield significantly more porous materials than other methods. This paper explores the connections between pathway, polymer defectivity, and microporosity. Using a network disassembly strategy, we show that defectivity highly approach defective polymers are associated with lower surface areas pore volumes. empirical association corroborated...
Inhaled nitric oxide (iNO) is a promising therapy for wide variety of pulmonary conditions but limited by the cost, portability, and safety limitations compressed gas cylinders used in conventional iNO delivery systems. On-demand generation via thermally controlled decomposition an NO-genic precursor attractive alternative to systems based on cylinders. However, most NO-releasing materials, which would form basis such system, are designed in-vivo applications, not flow release at elevated...
Abstract Porous aromatic framework (PAF) microporosity is known to be strongly dependent on synthetic approach but little about why certain reactions yield significantly and consistently more porous PAFs. This article explores the connections between pathway, PAF defectivity, microporosity. Using a network disassembly strategy, we show that defectivity highly defective PAFs are associated with lower surface areas pore volumes. empirical association corroborated through systematic...
ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to "Catalytically Relevant Intermediates in the Ni-Catalyzed C(sp2)–H and C(sp3)–H Functionalization of Aminoquinoline Substrates"Pronay RoyPronay RoyMore by Pronay Royhttps://orcid.org/0000-0002-5649-8747, James R. BourJames BourMore Bourhttps://orcid.org/0000-0002-0372-7323, Jeff W. KampfJeff KampfMore Kampfhttps://orcid.org/0000-0003-1314-8541, Melanie S. Sanford*Melanie...