Chemistry Commons^™

Benzosiloles With Crystallization-Induced Emission Enhancement Of Electrochemiluminescence: Synthesis, Electrochemistry, And Crystallography, Liuqing Yang, Donghyun Koo, Jackie Wu, Jonathan M. Wong, Tyler Day, Ruizhong Zhang, Harshana Kolongoda, Kehan Liu, Jian Wang, Zhifeng Ding, Brian Pagenkopf

Chemistry Publications

Crystallization-induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 times and 16 times. The mechanism of the CIEE-ECL was examined by spooling ECL spectroscopy, X-ray crystal structure analysis, photoluminescence, and DFT calculation. This CIEE-ECL system is a complement to the well-established aggregation-induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.

Synthesis Of Functionalized Tetrahydropyridines By Sncl4-Mediated [4+2] Cycloaddition Between Donor–Acceptor Cyclobutanes And Nitriles, David Tong, Jackie Wu, Nathan Bazinski, Donghyun Koo, Naresh Vemula, Brian Pagenkopf

Chemistry Publications

Cycloadditions of strained carbocycles promoted by Lewis acids are powerful methods to construct heterocyclic frameworks. In fact, the formal [3+2] cycloadditions of donor-acceptor (DA) cyclopropanes with nitriles has seen particular success in synthesis. In this work, we report on the first [4+2] cycloaddition of nitriles with DA cyclobutanes via Lewis acid activation. Tetrahydropyridine derivatives were obtained in up to 91% yield from various aryl activated cyclobutane diesters and aliphatic or aromatic nitriles.

Acid-Mediated N-Iodosuccinimide-Based Thioglycoside Activation For The Automated Solution-Phase Synthesis Of Α-1,2-Linked-Rhamnopyranosides, Victoria R. Kohout, Alyssa L. Pirinelli, Nicola L.B. Pohl

Chemistry Publications

Carbohydrate structures are often complex. Unfortunately, synthesis of the range of sugar combinations precludes the use of a single coupling protocol or set of reagents. Adapting known, reliable bench-chemistry reactions to work via automation will help forward the goal of synthesizing a broad range of glycans. Herein, the preparation of di- and tri-saccharides of alpha 1→2 rhamnan fragments is demonstrated using thioglycoside donors with the development for a solution-phase-based automation platform of commonly used activation conditions using N-iodosuccinimide (NIS) with trimethylsilyl triflate. Byproducts of the glycosylation reaction are shown to be compatible with hydrazine-based deprotection conditions, lending broader functionality …

Organic Chemistry With A Biographical Emphasis: Solutions To In-Chapter Exercises, Timothy Soderberg

Chemistry Publications

The solutions to the in-chapter exercises of Organic Chemistry with a Biological Emphasis volume 1 and 2.

Organic Chemistry With A Biological Emphasis: Solutions To Selected End-Of-Chapter Problems, Timothy Soderberg

Chemistry Publications

The solutions to the in-chapter exercises of Organic Chemistry with a Biological Emphasis volume 1 and 2.

Organic Chemistry With A Biological Emphasis Volume Ii, Timothy Soderberg

Chemistry Publications

The traditional approach to teaching Organic Chemistry, taken by most of the textbooks that are currently available, is to focus primarily on the reactions of laboratory synthesis, with much less discussion - in the central chapters, at least - of biological molecules and reactions. This is despite the fact that, in many classrooms, a majority of students are majoring in Biology or Health Sciences rather than in Chemistry, and are presumably taking the course in order to learn about the chemistry that takes place in living things.

In an effort to address this disconnect, I have developed a textbook for …

Organic Chemistry With A Biological Emphasis Volume I, Timothy Soderberg

Chemistry Publications

The traditional approach to teaching Organic Chemistry, taken by most of the textbooks that are currently available, is to focus primarily on the reactions of laboratory synthesis, with much less discussion - in the central chapters, at least - of biological molecules and reactions. This is despite the fact that, in many classrooms, a majority of students are majoring in Biology or Health Sciences rather than in Chemistry, and are presumably taking the course in order to learn about the chemistry that takes place in living things.

In an effort to address this disconnect, I have developed a textbook for …

Synthesis, Self-Assembly, And Immunological Activity Of Α-Galactose-Functionalized Dendron–Lipid Amphiphiles, John Trant, Namrata Jain, D. M. Mazzuca, J Trevor Mcintosh, Bo Fan, S M Mansour Haeryfar, Sebastien Lecommandoux, Elizabeth Gillies

Chemistry Publications

Nanoassemblies presenting multivalent displays of biologically active carbohydrates are of significant interest for a wide array of biomedical applications ranging from drug delivery to immunotherapy. In this study, glycodendron–lipid hybrids were developed as a new and tunable class of dendritic amphiphiles. A modular synthesis was used to prepare dendron–lipid hybrids comprising distearylglycerol and 0 through 4th generation polyester dendrons with peripheral protected amines. Following deprotection of the amines, an isothiocyanate derivative of C-linked α-galactose (α-Gal) was conjugated to the dendron peripheries, affording amphiphiles with 1 to 16 α-Gal moieties. Self-assembly in …

Oxidative Cyclization Of Tertiary Pentenol Derivatives Forming 2,5,5-Trisubstituted Thf Rings And The Total Synthesis Of Cyclocapitelline, Geoffrey A. Phillips, Cory Palmer, Andrew C. Stevens, Mattew L. Piotrowski, Daryyl Sr Dekruyf, Brian Pagenkopf

Chemistry Publications

The synthesis of 2,5,5-trisubstituted tetrahydrofuran rings was accomplished via the Mukaiyama aerobic oxidative cyclization of tertiary 5-pentenols employing the Co(nmp)₂catalyst. A variety of THFs were formed in moderate to good yield and diastereoselectivity. The method developed herein was successfully applied to an enantioselective total synthesis of cyclocapitelline.

Synthesis Of (+)-Bovidic Acid, Geoffrey A. Phillips, Timothy B. Wright, Andrew C. Stevens, Brian Pagenkopf

Chemistry Publications

(+)-Bovidic acid is an 18-carbon hydroxyfuranoid acid isolated from the pelage of the gaur (Bosfrontalis) and displays potential as an insect repellant. Both a formal and total synthesis of (+)-bovidic acid was carried out with the core of the natural product being synthesized through Mukaiyama aerobic oxidative cyclization employing the second-generation Co(nmp)₂ catalyst.

The [4+2] Cycloaddition Of Donor-Acceptor Cyclobutanes And Nitrosoarenes., Naresh Vemula, Andrew C Stevens, Tyler B Schon, Brian L Pagenkopf

Chemistry Publications

The Yb(OTf)3 catalyzed [4+2] cycloaddition between donor-acceptor cyclobutanes and nitrosoarenes is disclosed. This method facilitates the synthesis of tetrahydro-1,2-oxazines in good to excellent yields as single diastereomers. Except for a few electron-deficient nitrosoarenes, excellent regioselectivity was observed throughout these studies.

Bf2obn∙Oet2: A Novel Lewis Acid And Its Use In A Regio- And Stereo-Selective Opening Of Trisubstituted Epoxides And Its Application Towards Amphidinolide C, Nicholas A. Morra, Brian Pagenkopf

Chemistry Publications

The generation of a new Lewis acid (BF2OBn·OEt2) has been reported, and its usefulness has been demonstrated in the regio- and stereoselective ring-opening of trisubstituted epoxides. This Lewis acid is one in a series of new Lewis acids generated from BF3·OEt2 that display varying levels of Lewis acidity. When paired with a modified Shi epoxidation protocol, highly functionalized propionate units, such as those found in a wide variety of natural products, can be accessed. In conjunction with a Mukaiyama oxidative cyclization employing our second generation catalyst Co(nmp)2, this procedure ultimately culminated in the shortest and highest yielding route towards the …

Gram Scale Synthesis Of The C(18)-C(34) Fragment Of Amphidinolide C., Nicholas A Morra, Brian L Pagenkopf

Chemistry Publications

The synthesis of the C(18)-C(34) fragment of amphidinolide C has been achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. The highly convergent approach will facilitate the synthesis of analogues, including the C(18)-C(29) fragment of amphidinolide F. Synthetic highlights include the selective methylation of a diyne, and the highly efficient use of a second generation cobalt catalyst in the Mukaiyama oxidative cyclization to form the trans-THF ring.