Past Seminars & Events

Yiming Wang

Assistant Professor

Chemistry Department

University of Pittsburgh

Abstract

“Cationic Late Transition Metal Complexes for Selective α-C–H Functionalization”

We describe the discovery and development of catalytic α-C–H functionalization reactions of simple unsaturated hydrocarbons, including alkynes, alkenes, and allenes, using cationic cyclopentadienyliron (II) dicarbonyl complexes. These complexes enable the development of a new mode of catalytic C–H functionalization in which metal coordination to a π-bond facilitates the deprotonation of a neighboring C–H bond. The implementation of this strategy resulted in mild, functional group tolerant, and regioselective transformations for the coupling of unsaturated hydrocarbons with aldehydes, iminiums, and other readily available or easily accessed carbon electrophiles. Investigations into the reaction mechanism and the discovery and optimization of new ligand systems are discussed. Extensions of this approach to other transition metal catalysts for stereoselective transformations are also described.

Yiming Wang

Yiming Wang was born in Shanghai, China and grew up in Colorado, USA. He graduated with an A.B./A.M. degree in chemistry & physics and mathematics from Harvard University in 2008 after conducting research in the group of Professor Andrew Myers. After obtaining his Ph.D. under the supervision of Professor Dean Toste at the University of California, Berkeley in 2013, he conducted postdoctoral research in the laboratory of Professor Stephen Buchwald at the Massachusetts Institute of Technology as a National Institutes of Health Postdoctoral Fellow. He joined the Department of Chemistry at the University of Pittsburgh in Fall 2017.

Dr. Kimberly Schultz

Senior Product Development Specialist, 3M Company

Printable Flyer

Celebrating Women Chemists Lunch Seminar Series

The Celebrating Women Chemists lunch seminar series, hosted by the Women in Science and Engineering (WISE) Chemistry Chapter, provides a forum for networking across the various subdivisions of chemistry and fosters a sense of community among participants. These presentations are an opportunity for women chemists to share information about their unique career paths in a way to help inform students and postdocs in our department on the variety of opportunities they can pursue. These seminars are open to all, but we especially encourage women, including graduate students, postdocs, faculty and staff, to attend. This month’s speaker is Dr. Kimberly Schultz, Senior Product Development Specialist at 3M.

Women in Science and Engineering (WISE) Chemistry Chapter

The Chemistry WISE team provides a networking resource for women graduate students and post-docs in the department, with the goal of increasing the recruitment and retention of women, and improving the climate for all chemists.

Contact: Polly Lynch, CWC Luncheon Coordinator lynch764@umn.edu

Dr. Vinícius Wilian D. Cruzeiro

Department of Chemistry

Stanford University

Abstract

“Pushing boundaries in computational chemistry: describing quantum effects in large and complex systems with accelerated calculations”

Computational chemistry acts as a “virtual microscope” that em- ploys quantum mechanics (or approximations to it) to allow us to observe the behavior of matter at the atomic level. These computational simulations not only advance our understanding of experimental observations but can even be used to guide experimental designs. Therefore, innovations that extend existing methods in new directions or that make the calculations faster are essential to push the computational chemistry field forward, allowing for novel and more complex systems to be explored. In this talk, we will examine three cases where limitations in existing methods were surpassed and applied to address a range of different chemical problems. First, we will see how – despite limitations in classical force fields to describe bond breaking/formation and electron transfer – we were able to use classical force fields to describe pH and redox effects in proteins. Then, we will see how to exploit the power of GPU-acceleration in quantum calculations while connect- ing quantum chemistry programs with third-party consumers in an efficient and easy-to-use way. Lastly, we will examine quantitative predictions in atmospheric chemistry for the reactive uptake of N2O5 by aerosol particles, which is notable as experimental measurements of this process are particularly difficult to obtain, but computational chemistry provided insight into the reaction mechanism. Taken together, these studies show exciting applications of computational chemistry that either directly provided new insights to experimental observations or were performed in situations where experimental measures are inaccessible.

Vinícius Wilian D. Cruzeiro

Dr. Vinícius Cruzeiro is currently a postdoctoral researcher at Stanford University working with Professor Todd Martínez at the Department of Chemistry. Dr. Cruzeiro obtained his Ph.D. in Chemistry from the University of Florida working with Professor Adrian Roitberg. Dr. Cruzeiro’s research with computational/theoretical chemistry aims at accurately describing the behavior of proteins, biomolecules, and related systems using molecular simulations, quantum mechanics, and machine learn- ing representations while leveraging collaborations with experimentalists. Dr. Cruzeiro develops methodologies and software for molecular simulations and electronic structure calculations, including simulations to pre-dict coupled electrochemical and pH effects, enhanced sampling techniques, and quantum mechanics/molecular mechanics approaches. Some of Dr. Cruzeiro’s recent research interests include elucidating enzyme-catalyzed reaction mechanisms, making quantum calculations more accessible and efficient, describing the X-ray emission spectrum of liquid water, and providing quantitative predictions about the reactive update of N2O5 by aerosol particles in atmospheric chemistry.

Lisa A. Fredin

Assistant Professor

Chemistry Department

Lehigh University

Abstract

“Modeling Photoactive Organic Materials”

Chemical intuition is well developed for single molecules but the extent to which disorder in solid state molecular materials contributes to their properties is poorly understood. In particular, molecular materials move charges in some directions much more efficiently than others due to the packing of the molecules. Noncovalent interactions between the molecular components mean that dynamic disorder in these materials can have a large impact on the electronic properties of these materials at room temperature. This work explores how packing and vibrations in organic crystals affect charge transport in light driven devices. In particular, the size of dynamic disorder due to phonons or electronic excitation of molecules in the crystal is predicted for well-ordered high-mobility single crystals.

Lisa A. Fredin

Lisa A. Fredin is an Assistant Professor of Chemistry at Lehigh University. Her research draws on her background combining experiment and theory to develop computational and theoretical models of fundamental electronic properties to design materials with targeted properties. The Fredin group develops models of the chemistry and physics of a broad range of disordered materials, bridging physical chemistry, material science, nanoscience, and computation; as well as, probing the boundaries of the particle and wave approximations of electrons in materials.

Professor Fredin earned a doctorate in chemistry at Northwestern University, and a bachelor’s in chemistry, biochemistry and applied mathematics (minor in computer science) at the University of Texas
at Austin. Before coming to Lehigh, Fredin served as a research chemist at the National Institute of Standards and Technology in Gaithersburg, Maryland.

Professor Brent Sumerlin

Department of Chemistry

George & Josephine Butler Polymer Research Laboratory

University of Florida

Abstract

“Photocatalysis to synthesize, derivatize, depolymerize, and degrade polymers”

Relying solely on mild ultraviolet or visible light irradiation of thiocarbonylthio compounds, we have developed a new avenue to polymer-protein conjugates, semi-telechelic polymers, and well-defined ultrahigh molecular weight (UHMW) block polymers. Using either a photocatalyst or relying on the direct activation of photoactive functional groups, we are able to (i) synthesize polymers by photoiniferter polymerization and (ii) install new functionality to these polymers to prepare copolymers of (meth)acrylates and olefins that are inaccessible by direct copolymerization. Extending these approaches to the rapidly growing field of photocatalytic decarboxylation, we were also able to prepare
photodegradable polymers that have all-carbon backbones. Most recently, we have demonstrated that by employing the traditional conditions of photopolymerization at elevated temperatures, we are able to achieve dramatically accelerated depolymerization to regenerate monomer, suggesting low-energy photochemistry can be leveraged to approach life-cycle circularity.

Brent Sumerlin

Brent Sumerlin is the George Bergen Butler Chair in the Department of Chemistry at the University of Florida. He received his undergraduate degree from North Carolina State University in 1998 and later earned his PhD in Polymer Science & Engineering at the University of Southern Mississippi under the guidance of Charles McCormick. After completing his PhD, Sumerlin worked as a Visiting Assistant Professor/Postdoctoral Research Associate at Carnegie Mellon University under Krzysztof Matyjaszewski. In 2005, he took a faculty position at Southern Methodist University before moving to the University of Florida in 2012. Sumerlin is an associate editor for ACS Macro Letters and a
Fellow of the Royal Society of Chemistry. He has received numerous awards, including the Alfred P. Sloan Research Fellowship, NSF CAREER Award, ACS Leadership Development Award, Journal of Polymer Science Innovation Award, Biomacromolecules/Macromolecules Young Investigator Award, the Hanwha-Total IUPAC Award, and the UF Doctoral Dissertation Mentoring/Advising Award.

Guowei Wei, Ph.D.

Foundation Professor

Department of Mathematics; Biochemistry & Molecular Biology; Electrical & Computer Engineering

Michigan State University

Abstract

“Mechanisms of SARS-CoV-2 Evolution and Transmission”

Discovering the mechanisms of SARS-CoV-2 evolution and transmission is one of the greatest challenges of our time. By integrating artificial intelligence (AI), viral genomes isolated from patients, tens of thousands of mutational data, biophysics, bioinformatics, and algebraic topology, the SARS-CoV-2 evolution was revealed to be governed by infectivity-based natural selection in early 2020 (J. of Mole. Biol. 2020, 432, 5212-5226). Two key mutation sites, L452 and N501 on the viral spike protein receptor-binding domain (RBD), were predicted in summer 2020, long before they occur in prevailing variants Alpha, Beta, Gamma, Delta, Kappa, Theta, Lambda, Mu, and Omicron. Our recent studies identified a new mechanism of natural selection: antibody resistance (J. Phys. Chem. Lett. 2021, 12, 49, 11850–11857). AI-based forecasting of Omicron’s infectivity, vaccine breakthrough, and antibody resistance was later nearly perfectly confirmed by experiments (J. Chem. Inf. Model. 2022, 62, 2, 412–422). The replacement of dominant BA.1 by BA.2 in later March was foretold in early February (J. Phys. Chem. Lett. 2022, 13, 17, 3840–3849). On May 1, 2022, we projected Omicron BA.4 and BA.5 to become the new dominating COVID-19 variants (arXiv:2205.00532). This prediction became reality in late June. Our models accurately forecast mutational impacts on the efficacy of monoclonal antibodies (mAbs).

Guowei Wei, Ph.D.

Guowei Wei earned his Ph.D. degree from the University of British Columbia in 1996. He was awarded a post-doctoral fellowship from the NSERC of Canada to pursue his postdoctoral work at the University of Houston. In 1998, he joined the faculty of the National University of Singapore and was promoted to Associate Professor in 2001. In 2002, he relocated to Michigan State University, where he is an MSU Foundation Professor of Mathematics, Electrical and Computer Engineering, and Biochemistry and Molecular Biology. His current research interests include mathematical foundations of data science and biosciences, deep learning, drug discovery, and computational geometry, topology, and graph. Dr. Wei has served extensively in a wide variety of national and international panels, committees, and journal editorships. His work was reported in numerous news and media articles.

Hans Renata

Associate Professor

Department of Chemistry

Rice University

Abstract 

“Combining Synthetic Chemistry and Biology for Streamlining Access to Complex Molecules”

By virtue of their unrivaled selectivity profiles, enzymes possess re markable potential to address unsolved challenges in chemical synthesis. The realization of this potential, however, has only recently gained traction. Recent advances in enzyme engineering and genome mining have provided a powerful platform for identifying and optimizing enzymatic transformations for synthetic applications and allowed us to begin formulating novel synthetic strategies and disconnections. This talk will describe our recent efforts in developing a new design language in chemical synthesis that centers on the incorporation of biocatalytic approaches in contemporary synthetic logic. Case studies will focus on the use of this platform in the chemoenzymatic syntheses of complex natural products and also highlight how this platform could serve as a starting point to enable further biological and medicinal chemistry discoveries.

Hans Renata

Hans Renata received his B.A. degree from Columbia University in 2008, conducting research under the tutelage of Professor Tristan H. Lambert. He earned his Ph.D. from The Scripps Research Institute in 2013 under the guidance of Professor Phil S. Baran. After postdoctoral studies with Professor Frances H. Arnold at the California Institute of Technology, he started his independent career at The Scripps Research Institute in 2016. In 2022, he moved to Rice University as an Associate Professor and CIPRIT Scholar. His research focuses on natural product synthesis and biocatalytic reaction developments. For these efforts, he has received several notable awards, such as the NSF CAREER award, the Sloan fellowship, the Chemical and Engineering News “Talented 12” award and the Arthur C. Cope Scholar award.

Sponsored by Organic Syntheses and AbbVie

Dr. Russell D. Cink

Senior Principal Research Scientist

AbbVie

Abstract

“Process Development of Glecaprevir”

Glecaprevir was identified as a potent hepatitis C virus (HCV) protease inhibitor, and an enabling synthesis was required to support early clinical trials. The key steps in the enabling route involved a ring-closing metathesis (RCM) reaction to form the 18-membered macrocycle and a challenging fluorination step to form a key difluoromethyl-substituted cyclopropyl amino acid. To support the late-stage clinical trials and subsequent commercial launch, a large-scale synthetic route to glecaprevir was required. The large-scale route to the macrocycle employed a unique intramolecular etherification reaction as the key step. The large-scale route to the difluoromethyl-substituted cyclopropyl amino acid avoided the fluorination challenges by constructing the amino acid from a commercially available difluoromethyl-substituted hemi-acetal. The key steps in the amino acid synthesis were a Knoevenagel condensation, a Corey- Chaykovsky cyclopropanation, a Curtius rearrangement, and a chiral resolution. Subsequent coupling of the macrocycle to the amino acid containing sidechain produced glecaprevir in 16% overall yield.

Russell D. Cink

Russell D. Cink graduated from the University of Minnesota in 1991 with a B.S. in Chemical Engineering. While an undergraduate, he conducted research under the direction of Wayland E. Noland which sparked his interest in synthetic organic chemistry. After working for 2 years as a consultant, he returned to the University of Minnesota and obtained a Ph.D. in Chemistry in 1998 under the direction of Craig J. Forsyth. Since 1998 he has worked as a process chemist at Abbott / AbbVie, primarily focused on small molecule process development and antibody drug conjugates.

Sponsored by Organic Syntheses and AbbVie

Professor Jesús M. Velázquez

Department of Chemistry

University of California, Davis

Abstract

“Establishing Structure—Function Relationships in Metal Sulfide Electrocatalysts to Drive CO2 and CO Conversion to Alcohols”

The development of solid-state synthetic pathways of earth abundant materials that address the growing dichotomy of simultaneously increasing energy demands and carbon emissions is an imperative that has progressively affected energy-related research efforts. An emerging technical avenue in this area is the conversion of vastly abundant renewable energy sources that can be harnessed and directed towards the synthesis of traditionally fossil fuel-based products from atmospheric feedstocks like CO2. To this end, our work establishes structure—function relationships for solid-state materials within the multinary chalgogenides comprised of MX2 (M = Mo, W; X = S, Se) and Chevrel-Phase (CP) MyMo6X8 (M = alkali, alkaline, transition or post-transition metal; y = 0-4; X = S, Se, Te) chalcogenides. The molybdenum sulfide structures from both families exhibit exceptional promise as CO2R catalysts. Furthermore, we have identified the CP catalyst framework as being selective towards the electrochemical reduction of CO2 and CO to methanol (only major liquid- phase product) under applied potentials as mild as -0.4 V vs RHE. Reactivity toward the electrochemical reduction of CO2 and CO to methanol is correlated with increased population of chalcogen states, as confirmed via X-Ray Absorption Spectroscopy. Overall, this work seeks to unravel optimally reactive small- molecule reduction catalyst compositions.

Jesús M. Velázquez

Jesús M. Velázquez is an Assistant Professor in the Department of Chemistry at UC Davis. He leads a research program centered on the rational design of well-defined solid-state materials at the meso and nanoscale. The target materials have immediate applications in energy conversion devices and environmental remediation. Characterization of the physicochemical properties of these materials involves a combination of microscopy, spectroscopy, electrochemistry, and synchrotron-based methods and will facilitate the development of structure—function correlations that will iteratively inform solid-state materials design. He received his B.S. in Chemistry from the University of Puerto Rico at Cayey. His doctoral degree in Chemistry was at SUNY Buffalo and he then transitioned to a Postdoctoral appointment in the Division of Chemistry and Chemical Engineering at Caltech. Recent recognitions for his research program at UCDavis include an NSF CAREER Award, Camille Dreyfus Teacher-Scholar Award, Cottrell Scholar Award, C&EN Talented 12, APS Stanford R. Ovshinsky Sustainable Energy Fellowship Award, two separate Scialog Fellowships, and the University of California CAMPOS Scholar distinction.

Velazquez’s research and education efforts have been featured in journal special issues such as the Journal of Materials Chemistry Emerging Investigator, I&EC Research’s 2021 Class of Influential Researchers Issue, Journal of Chemical Education-Diversity, Equity, Inclusion, and Respect in Chemistry Education Research and Practice as well as Chemistry of Materials “Up and Coming” early career scientist.

David Laviska, Ph.D

Portfolio Manager for Green Chemistry & Sustainability in Education

American Chemical Society

Abstract

“Green and sustainable chemistry: What is it? and why should you care?”

A quarter century ago, few people had heard the term “green chemistry” and there was a lot of confusion about what it meant. Since then, chemists (and scientists across all disciplines) have started to recognize the value in thinking broadly about the impact of their experiments, research, manufacturing processes, etc. In our global community, the word “green” has become connected with a broad spectrum of vaguely “environment- related” ideas and initiatives. But “green chemistry” refers specifically to a beautifully complex, holistic view of chemical reactions that takes account of everything from the sourcing of reagents (are they renewable?) to energy consumption, to the impact of by-products and disposal of waste materials. Broadly speaking, these latter variables are also intimately connected with the ubiquitous term “sustainability”; so much so, that it’s hard to imagine a future on our planet in which green chemistry doesn’t permeate every part of the global chemistry enterprise. In this talk, I will comment on what green chemistry is (and isn’t) and describe how it has shaped my career through various stages, including a “first career” at the USEPA as an environmental specialist, followed by more than a decade of teaching and research in academia, and finally, to my current position at the American Chemical Society Green Chemistry Institute. I will discuss both challenges and opportunities regarding the propagation of green chemistry and share some details of the goals we’re committed to accomplishing with your help.

David Laviska, Ph.D

David A. Laviska is the Portfolio Manager for Green Chemistry and Sustainability in Education. Prior to joining the ACS GCI, he was an Assistant Professor at Seton Hall University where he is co-director of the Academy for Green Chemistry, Stewardship, and Sustainability. As a pedagogical innovator, he led the effort to incorporate the principles of Green Chemistry throughout the Organic and General Chemistry curricula and was recognized by the College of Arts and Sciences as “Professor of the Year” in 2020. As a first generation college student and member of the LGBTQIA+ community, he took leading roles in working with undergraduate STEM students from across the spectrum of underrepresented groups. His research focuses on green(er) synthesis and characterization of late transition metal complexes with unique optical properties and hetero- and homogeneous catalysis. His research students also develop and pilot green(er) experimental protocols for use in undergraduate teaching labs. Prior to his second career in academia, Dr. Laviska worked for more than a decade as an Environmental/ Analytical Specialist with the EPA (Region II) and earned degrees in chemistry from Rutgers University (Ph.D.), University of Washington (M.S), and Cornell University (B.A.).