William F. Bailey

Bio: William F. Bailey is an academic researcher from University of Connecticut. The author has contributed to research in topics: Lithium & Ring (chemistry). The author has an hindex of 37, co-authored 199 publications receiving 4221 citations. Previous affiliations of William F. Bailey include University of Pittsburgh & University of Illinois at Urbana–Champaign.

Mechanism of the oxidation of alcohols by oxoammonium cations.

Abstract: The mechanism of the oxidation of primary and secondary alcohols by the oxoammonium cation derived from 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has been investigated computationally at the B3LYP/6-31+G* level, along with free energies of solvation, using a reaction field model. In basic solution, the reaction involves formation of a complex between the alkoxide anion and the oxoammonium cation in a pre-oxidation equilibrium wherein methoxide leads to a much larger formation constant than isopropoxide. The differences in free energy of activation for the rate-determining hydrogen transfer within the pre-oxidation complexes were small; the differences in complex formation constants lead to a larger rate of reaction for the primary alcohol, as is observed experimentally. In acidic solution, rate-determining hydrogen atom transfer from the alcohol to the oxoammonium cation had a large unfavorable free energy change and would proceed more slowly than is observed. A more likely path involves a hydride tran...

Conformational Studies in the Cyclohexane Series. 1. Experimental and Computational Investigation of Methyl, Ethyl, Isopropyl, and tert-Butylcyclohexanes.

Abstract: The conformational enthalpy (ΔH°), entropy (ΔS°), and free energy (−ΔG°) of methyl- (1), ethyl- (2), and isopropylcyclohexane (3) have been reinvestigated both experimentally and computationally. A novel experimental approach to evaluation of highly biased conformational equilibria is described that obviates the need to measure large axial/equatorial isomer ratios directly in order to determine the equilibrium constant: the natural abundance 13C signal for the C(2,6) resonance in the equatorial isomer of an alkylcyclohexane may be used as an internal reference, and the ratio of this band area to that of an enriched 13C nucleus in the axial isomer gives K following correction for statistical differences and the differing 13C-content of the signals being monitored. The experimental conformational enthalpies (ΔH°), determined at 157 K in independent studies at two laboratories, were found to be (kcal/mol) 1.76 ± 0.10 (Me), 1.54 ± 0.12 (Et), and 1.40 ± 0.15 (i-Pr); the corresponding conformational entropies ...

The Halogen Bond

Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

TEMPO-oxidized cellulose nanofibers

Abstract: Native wood celluloses can be converted to individual nanofibers 3–4 nm wide that are at least several microns in length, i.e. with aspect ratios >100, by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation and successive mild disintegration in water. Preparation methods and fundamental characteristics of TEMPO-oxidized cellulose nanofibers (TOCN) are reviewed in this paper. Significant amounts of C6 carboxylate groups are selectively formed on each cellulose microfibril surface by TEMPO-mediated oxidation without any changes to the original crystallinity (∼74%) or crystal width of wood celluloses. Electrostatic repulsion and/or osmotic effects working between anionically-charged cellulose microfibrils, the ζ-potentials of which are approximately −75 mV in water, cause the formation of completely individualized TOCN dispersed in water by gentle mechanical disintegration treatment of TEMPO-oxidized wood cellulose fibers. Self-standing TOCN films are transparent and flexible, with high tensile strengths of 200–300 MPa and elastic moduli of 6–7 GPa. Moreover, TOCN-coated poly(lactic acid) films have extremely low oxygen permeability. The new cellulose-based nanofibers formed by size reduction process of native cellulose fibers by TEMPO-mediated oxidation have potential application as environmentally friendly and new bio-based nanomaterials in high-tech fields.

Domino Reactions in Organic Synthesis

Abstract: Introduction Cationic domino reactions Anionic domino reactions Radical domino reactions Pericyclic domino reactions Photochemically induced domino processes Transition metal catalysis Domino reactions initiated by oxidation or reduction Enzymes in domino reactions Multicomponent reactions Special techniques in domino reactions

C-F bond activation in organic synthesis.

Abstract: Fluorine has received great attention in all fields of science. “Small atom with a big ego” was the title of the Symposium at the ACS meeting in San Francisco in 2000, where a number of the current scientific and industrial aspects of fluorine chemistry made possible by the small size and high electronegativity of the atom were discussed. This small atom has provided mankind with significant benefits in special products such as poly(tetrafluroethylene) (PTFE), freon, fluoro-liquid crystals, optical fiber, pharmaceutical and agrochemical compounds, and so on, all of which have their own unique properties that are otherwise difficult to obtain.1 For instance, at present, up to 30% of agrochemicals and 10% of pharmaceuticals currently used contain fluorine atoms. Therefore, organic fluorine compounds have received a great deal of interest and attention from the scientists involved in diverse fields of science and technology. Now, not only C-F bond formation but also selective C-F bond activation have become current subjects of active investigation from the viewpoint of effective synthesis of fluoroorganic compounds. The former is highlighted by designing a sophisticated fluorinating reagent for regioand stereocontrolled fluorination and developing versatile multifunctional and easily prepared building blocks. C-F bond formation has been treated extensively in several reviews2 and books.3 The latter is a subject that has been less explored but would be promising for selective defluorination of aliphatic fluorides, cross-coupling with aryl fluorides, and * To whom correspondence should be addressed. Phone: 81-78-803-5799. Fax: 81-78-803-5799. E-mail: amii@kobe-u.ac.jp and uneyamak@cc.okayamau.ac.jp. † Kobe University. ‡ Okayama University. Chem. Rev. 2009, 109, 2119–2183 2119

Direct photosynthetic recycling of carbon dioxide to isobutyraldehyde

Abstract: Global climate change has stimulated efforts to reduce CO(2) emissions. One approach to addressing this problem is to recycle CO(2) directly into fuels or chemicals using photosynthesis. Here we genetically engineered Synechococcus elongatus PCC7942 to produce isobutyraldehyde and isobutanol directly from CO(2) and increased productivity by overexpression of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). Isobutyraldehyde is a precursor for the synthesis of other chemicals, and isobutanol can be used as a gasoline substitute. The high vapor pressure of isobutyraldehyde allows in situ product recovery and reduces product toxicity. The engineered strain remained active for 8 d and produced isobutyraldehyde at a higher rate than those reported for ethanol, hydrogen or lipid production by cyanobacteria or algae. These results underscore the promise of direct bioconversion of CO(2) into fuels and chemicals, which bypasses the need for deconstruction of biomass.