Index Catalog // ScholarsArchive@OSU

Rationalization and innovative design of asymmetric organocatalysts through computational investigation

Creator:: Johnston, Ryne Connell
Abstract:: My work on computing complex catalyzed organic transformations reveals that only a few subtle chemical factors, e.g. non-classical hydrogen bonding, (hyper)conjugation and steric effects, common across different catalyst manifolds are critical for catalysis and selectivity. Rational manipulation and exploitation of these factors has led to improved catalyst designs, which has...
Resource Type:: Dissertation
Full Text:: ABSTRACT OF THE DISSERTATION OF Ryne Connell Johnston for the degree of Doctor of Philosophy in

C–H···O Non-Classical Hydrogen Bonding in the Stereomechanics of Organic Transformations: Theory and Recognition

Creator:: Johnston, Ryne C. and Cheong, Paul Ha-Yeon
Abstract:: This manuscript describes the role of non-classical hydrogen bonds (NCHBs), specifically C–H···O interactions, in modern synthetic organic transformations. Our goal is to point out the seminal examples where C–H···O interactions have been invoked as a key stereocontrolling element and to provide predictive value in recognizing future and/or potential C–H···O interactions...
Resource Type:: Article
Full Text:: Ryne C. Johnston, Paul Ha-Yeon Cheong* Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth

Catalyst selective and regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates: synthetic and computational studies

Creator:: Gould, Eoin, Walden, Daniel M., Kasten, Kevin, Johnston, Ryne C., Wu, Jiufeng, Slawin, Alexandra M., Mustard, Thomas J. L., Johnston, Brittany, Davies, Tony, Cheong, Paul Ha-Yeon, and Smith, Andrew D.
Abstract:: The regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates is described, with DMAP giving preferential N-carboxylation and triazolinylidenes promoting selective C-carboxylation (both with up to >99 : 1 regioselectivity). An enantioselective O- to C-carboxyl variant using NHC catalysis is demonstrated (up to 92% ee), while mechanistic and DFT studies outline...
Resource Type:: Article
Full Text:: Daniel M. Walden,b Kevin Kasten,a Ryne C. Johnston,b Jiufeng Wu,a Alexandra M. Z. Slawin,a Thomas J. L

Studies towards the total synthesis of (-)-kendomycin

Creator:: Smits, Helmars
Abstract:: Studies towards the total synthesis of (−)-kendomycin (1), a bacterial metabolite with a unique molecular architecture and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediate 208, containing all of the carbon atoms of 1. A Dötz annulation between alkyne 122 and novel chromium carbenoid...
Resource Type:: Dissertation
Full Text:: -closing metathesis to provide (Z)-olefin 206. Transannular selenoetherification was the method of choice

Computational Investigation and Prediction of Mechanisms and Stereocontrol in Complex Organic Reactions

Creator:: Pattawong, Ommidala
Abstract:: Complex organic transformations, such as the addition of pyrrole to ketene using planar chiral organocatalyst (*PPY), the four-component anhydride- Manniach reactions, and the site-selective desymmetrization of meso-1,2-diol, are remarkable synthetic reactions that provide high yield and high selectivity. However, the exact mechanism and origins of stereocontrol for theses synthetic organic...
Resource Type:: Dissertation
Full Text:: CH···O interactions. The former differentiates the E/Z-catalyst enolates in the transition states

The tetra-alkyl ammonium compounds, their possible use in agriculture and industry

Creator:: Callaway, Edward Cleveland
Resource Type:: Masters Thesis
Full Text:: remained for two English chemists, Walker end Johnston, (1) to revive interest in tetra-alkyl ammonium

Computational Rationalizations of Mechanism and Stereocontrol in Small-Molecule Lewis Base Organocatalysis

Creator:: McCauley-Walden, Daniel W.
Abstract:: My work has focused on investigating synthetic organic reactions using applied computational methods. Non-covalent interactions are critical to catalysis, mechanism, and stereoselectivity, with the most prominent interaction for isothioureas being the S···O contact between the catalyst sulfur atom and the oxygen of the acyl group. A comprehensive joint experimental and...
Resource Type:: Dissertation
Full Text:: . Ryne Johnston, Maduka Ogba, Lindsay Wills, TJ Mustard, and Ommidalla Pattawong, you all set such a

Radiotracer studies of carbohydrate catabolism in tomato fruit

Creator:: Ramsey, John Charles
Abstract:: Glucose-1, -2 and -6-C¹⁴ substrates were incorporated into individual tomato fruits in order to study the catabolic fate of substrate glucose, especially with regard to the possible occurrence of triose recombination, as well as to investigate the pathways leading to the biosynthesis of C₄ acids in the fruit. After metabolizing...
Resource Type:: Dissertation
Full Text:: labeled substrates Measurement of radioactivity Incorporation of glucose-L, -Z and -5 -Cl4 Separation of

Approaches toward synthesis of the mycosporins

Creator:: Cammack, Janice H.
Abstract:: The mycosporins, formerly called P310's are secondary metabolites of fungi closely associated with fungal reproductive processes that require light. The structurally related iminomycosporins are found in marine plants and animals and may also have functions related to light. In this study, approaches toward the asymmetric synthesis of the mycosporins are...
Resource Type:: Dissertation

Molecular intensity parameters in the solid state

Creator:: Fredrickson, Larry R.
Resource Type:: Dissertation
Full Text:: ) 5 or alternately in the principal axis notation e = 1 + 47rP /E o- x, y, or z (8) 0 0- 0 By

ScholarsArchive@OSU

Rationalization and innovative design of asymmetric organocatalysts through computational investigation

C–H···O Non-Classical Hydrogen Bonding in the Stereomechanics of Organic Transformations: Theory and Recognition

Catalyst selective and regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates: synthetic and computational studies

Studies towards the total synthesis of (-)-kendomycin

Computational Investigation and Prediction of Mechanisms and Stereocontrol in Complex Organic Reactions

The tetra-alkyl ammonium compounds, their possible use in agriculture and industry

Computational Rationalizations of Mechanism and Stereocontrol in Small-Molecule Lewis Base Organocatalysis

Radiotracer studies of carbohydrate catabolism in tomato fruit

Approaches toward synthesis of the mycosporins

Molecular intensity parameters in the solid state

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