A5072703677- Organoboron and organosilicon chemistry
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Boron Compounds in Chemistry
- Organic Light-Emitting Diodes Research
- Chemical Synthesis and Analysis
- Organic Electronics and Photovoltaics
- Catalytic Cross-Coupling Reactions
- Coordination Chemistry and Organometallics
- Asymmetric Synthesis and Catalysis
- Luminescence and Fluorescent Materials
- Molecular Junctions and Nanostructures
- Synthesis and characterization of novel inorganic/organometallic compounds
- Chemical Synthesis and Reactions
- Boron and Carbon Nanomaterials Research
- Carbohydrate Chemistry and Synthesis
- Photochemistry and Electron Transfer Studies
- Synthesis and pharmacology of benzodiazepine derivatives
- Thin-Film Transistor Technologies
- Dyeing and Modifying Textile Fibers
- Asymmetric Hydrogenation and Catalysis
- Crystallography and molecular interactions
- Organophosphorus compounds synthesis
- Chemical Reaction Mechanisms
- Oxidative Organic Chemistry Reactions
Dow Chemical (United States)
2014-2017
Cornell University
2008-2013
University of Michigan
2007-2013
Ann Arbor Center for Independent Living
2012
University of Bristol
2009
Calvin University
2002
The first examples of borylation under conditions borenium ion generation from hydrogen-bridged boron cations are described. observable H-bridged generated by hydride abstraction N,N-dimethylamine boranes Ar(CH2)nNMe2BH3 using Ph3C+ (C6F5)4B− (TrTPFPB) as the acceptor. In presence excess TrTPFPB, undergo internal to afford cyclic amine borane derivatives with n = 1−3. products formed corresponding ions according reductive quenching experiments and 11B 1H NMR spectroscopy in case Ar C6H5 1....
Solid-state solvation (SSS) is analogous to liquid-phase but occurs within glassy matrices. Organic solutes with singlet charge transfer (1CT) excited states are especially susceptible solvatochromism. Their 1CT and photon emission energies decrease when surrounding molecules sterically unhindered polar moieties reorient stabilize them. Thermally activated delayed fluorescence (TADF) organic light-emitting diodes feature such as emitters in the solid state, employing efficient reverse...
Internal borylation occurs upon activation of aryl di-isopropylphosphinite boranes with HNTf(2) to give heterocyclic intermediates that can be reductively quenched afford 6 or treated KHF(2) the phenolic potassium trifluoroborate salts 10. The latter are useful for Pd-catalyzed coupling iodides under Molander conditions, provided precautions taken remove KNTf(2) byproduct from preceding step.
The method of continuous variation in conjunction with 6Li NMR spectroscopy was used to characterize lithium phenolates solvated by tetrahydrofuran and 1,2-dimethoxyethane. strategy relies on the formation ensembles homo- heteroaggregated phenolates. symmetries concentration dependencies heteroaggregates attest aggregation numbers homoaggregates. structurally diverse phenols afford substrate- solvent-dependent combinations phenolate monomers, dimers, trimers, tetramers, pentamers. We discuss...
Borenium ions do not accumulate under the conditions of hydride abstraction from Lewis base borane complexes (L·BH3) using trityl cation because subsequent rapid reaction with L·BH3 occurs to form B−H−B bonds. The hydride-bridged cations are sufficiently stabilized resist remaining by excess cation; however, reversible cleavage 3c2e bond does take place release borenium ion equivalents, as evidenced interaction weak nucleophiles.
Organic light-emitting diode (OLED) displays have been an active and intense area of research for well over a decade now reached commercial success from cell phones to large format televisions. A more thorough understanding the many different potential degradation modes which cause OLED device failure will be necessary develop next generation materials, improve lifetime, ultimately cost vs performance ratio. Each organic layers in can susceptible unique decomposition pathways, however...
Solid-state solvation (SSS) is a solid-state analogue of solvent-solute interactions in the liquid state. Although it could enable exceptionally fine control over energetic properties devices, its molecular mechanisms have remained largely unexplored. We use ultrafast transient absorption and optical Kerr effect spectroscopies to independently track correlate both excited-state dynamics an organic emitter polarization anisotropy relaxation small polar dopant embedded amorphous polystyrene...
Cationic cotton has a greater affinity for reactive dyes than untreated cotton, providing economic and environmental advantages the textile industry. The reaction by which cationic group is appended to suffers from competing hydrolysis in aqueous medium; inefficiency of cationization under desired processing conditions currently limits widespread application. A study kinetics processes provided insight into mechanism with enabled high-throughput parallel reactors. dependences on temperature...
A substituted anthraquinone (AQ), previously shown to photochemically generate benzaldehyde in methanol solution, was attached a commercially available resin via an 11 carbon tether and amide bond. Photolysis of the polymer-bound AQ with visible or 350 nm UV light resulted formation yields 50-55% as determined by HPLC. The phenolic positions polymer were then alkylated using benzyl bromide 1-iodo-3-(4-nitrophenyl)propane coupling reaction K(2)CO(3) base solution-phase proton shuttle. these...
The lithium enolate of tert-amylacetate solvated by N,N,N',N'-tetramethylethylenediamine (TMEDA) is shown to be a doubly chelated dimer. Adding the dimeric 4-fluorobenzaldehyde-N-phenylimine affords an N-lithiated β-amino ester monomeric using (6)Li and (15)N NMR spectroscopies. Rate studies (19)F spectroscopy reveal reaction orders consistent with transition structure stoichiometry [(ROLi)2(TMEDA)2(imine)](‡). Density functional theory computations explore several possible dimer-based...
Internal hydride transfer occurs when tethered carbocations are generated from unsaturated phosphine or phosphinite boranes. 3-Methylenecyclohexyl-derived boranes 12 18 react with MsOH to give ionic hydrogenation products high syn-selectivity. With amine boranes, initial hydrogen evolution gives BH2(OMs) complexes, but IH using excess in a slower second stage. A diastereoselective reaction 26b camphorsulfonic acid (first stage) and (second stage), affording 33 (68% ee) after hydrolysis.
Abstract Internal borylation occurs upon activation of aryl di‐isopropylphosphinite boranes with HNTf 2 giving heterocyclic intermediates leading either to (II) or phenolic potassium salts (VI).
Abstract Review: 179 refs.