UCLA

Chem 278: Prof. Lisa Olshansky
2021-11-17 16:00 (America/Los_Angeles)
“Conformational Control over Metal ion Reactivity”
Abstract: Metalloenzymes facilitate some of the most thermodynamically and kinetically challenging chemical transformation known, and in contrast to our industrial methods, they do so under extremely mild conditions. What are they doing that we are not? One aspect of metalloenzyme reactivity that is ubiquitous in nature yet often overlooked in the development of synthetic systems is the role that conformational gating steps play in mediating metallocofactor reactivity. Inspired by these enzymes, research in the Olshansky lab is focused on testing the hypothesis that conformational control represents an efficient means with which to control metal ion reactivity, promote electron and proton transfer steps, and mediate the interconversion of different forms of energy. However, naturally occurring metalloenzymes are extremely complex and studying them directly, it is often impossible to disentangle the interplay between conformation and reactivity, so instead, the Olshansky lab prepares and studies simplified model systems encapsulating this interplay. Through the construction of switchable artificial metalloproteins and coordination complexes, we are working to dissect the kinetic and thermodynamic consequences of conformational control, and we are preparing an array of switchable systems for applications in solar energy conversion, catalysis, and biomedicine.

Chem 218: Student Exit Seminar - Hannah Friedman
2021-11-18 12:00

The 2021 John D. Roberts Lecture - Physical Organic Chemistry on the Brain: Understanding the Nicotine Receptor
2021-11-18 16:00
The remarkable complexity of the human brain is evident at all levels, from anatomical to cellular to molecular. The central molecules of synaptic signaling comprise a diverse array of integral membrane proteins that are resistant to most approaches to high resolution structural characterization. As such, chemistry provides the most powerful tool for unraveling the structures and functions of the molecules of memory, thought, and sensory perception; of Alzheimer’s, Parkinson’s, and schizophrenia. Using the mindset and methodologies of physical organic chemistry, and combining them with molecular biology, electrophysiology, and computer modelling we have probed these complex membrane proteins with a precision and subtlety normally associated with small molecule studies. We have uncovered key interactions that allow agonists to bind, and that distinguish binding of natural ligands vs. substances of abuse, including a key cation-π interaction that enables tight binding of nicotine to specific regions of the brain.

Chem 268 - Steve Clarke and Roy Wollman
2021-11-19 15:30

Chem 228: Samanvaya Srivastava
2021-11-22 16:00
“Polyelectrolyte Complex-Based Robust and Tough Wet Adhesives”

Chem 278: Dr. Miguel Gonzalez
2021-12-01 16:00
“Controlling Chemistry through Confinement”

Chem 218: Student Exit Seminar - Derek Urwin
2021-12-02 12:00

Chem 268 - Cathy Clarke and Jose Rodriguez
2021-12-03 15:30

Chem 278: Prof. Manfred Scheer
2021-12-08 15:00
“The Close and Loose Relationship Between Carbon and Phosphorus”

CIC Careers in Green Chemistry Seminar Series
2021-12-09 13:00
The Center for Integrated Catalysis is hosting a new seminar series called the “Careers in Green Chemistry.” With these webinars, we aim to bring speakers from a wide variety of careers, linked through green chemistry, to come talk about their current job as well as the career path that led them to that position. We are pleased to invite all students, postdocs, and faculty.

Chem 278: Dr. Juyao Dong
2022-01-05 16:00
“Advances in Genome Editing Therapeutics at Intellia and Pharma Career Opportunities for Chemists”

POSTPONED! Chem 268 - Naomi Courtemanche
2022-01-07 15:30
“Actin filament assembly mediated by formins: All roads lead to the barbed end”

Chem 228: Robert Phillips and Christina Hueschen
2022-01-10 16:00
“A Language Whose Characters are Triangles”

POSTPONED - NSF Center for Integrated Catalysis Webinar Series
2022-01-11 10:30
POSTPONED – The NSF Center for Integrated Catalysis is delighted to announce that it will be hosting a monthly webinar series. The next webinar of this series will be held on Tuesday, January 11th, 2021 at 10:30 AM. We are pleased to invite all students, postdocs, faculty, and staff.

Special Physical Chemistry Seminar - Elsa Sanchez Garcia
2022-01-13 12:00
“CL-FEP: An Accurate End-State Free Energy Perturbation Approach”

Postponed: Chapman Lectureship
2022-01-13 16:00
The Chapman Lecture has been postponed until futher notice.

Stereoselective Gold Catalysis: From Metal-Ligand Cooperation to SN2 Glycosylation
2022-01-13 16:00
Abstract: Metal-ligand cooperation is a versatile strategy for achieving efficient and/or stereoselective catalysis. Since 2014, we have developed a range of enabling remotely basic group-functionalized biaryl-2-ylphospine ligands (see Scheme A) for cooperative gold catalysis. With chiral elements built into these ligands, asymmetric transformations are developed in mechanistically rational manners. DFT calculations confirm the critical participation of the ligand remote basic group in catalysis. Several recent developments will be discussed. This type of bifunctional ligands also enables cooperative catalysis by other metals including Cu and Ag.
A different yet related approach to achieving stereoselective gold catalysis is developed specifically to address the long-standing challenge in carbohydrate synthesis, i.e., the lack of stereoselective synthesis of glycosidic bonds applicable to every sugar type. In this approach, as shown in Scheme B, a basic group is installed onto the anomeric leaving group of the carbohydrate donor and serves to direct the backend attack by a carbohydrate acceptor upon the leaving group activation by gold. The SN2 nature of the glycosylation and the general tolerance of many sugar types make this approach appealing. The progress made in this area will be discussed.

POSTPONED! Chem 268 - Jennifer Niven Shepherd
2022-01-14 13:15
“Microbial rhodoquinone biosynthesis proceeds via an atypical RquA-catalyzed amino transfer
from S-adenosyl-L-methionine to ubiquinone”

POSTPONED - Chem 278: Prof. Shiyu Zhang
2022-01-19 16:00
“Modeling Enzymatic Reactivity with Copper Coordination Complexes”
POSTPONED

Chem 228: Gerard C. L. Wong
2022-01-24 16:00
“Molecular biomimicry by the SARS-CoV-2 virus: consequences for severe inflammation, coagulation, and dysregulation of antiviral responses”

Postponed
2022-01-27 16:00

Chem 268 - Dylan T. Burnette
2022-01-28 15:30
“How does a heart grow? A cell biologist wants to know”

CANCELLED! Chem 228: Steven Schwartz
2022-01-31 16:00
“Rare Event Sampling, Protein Dynamics in enzymatic catalysis and directed evolution: lessons in artificial enzyme design”

Chem 228: Professor Wei Xiong, UCSD
2022-01-31 16:00
Ultrafast Dynamics of Molecular Vibrational Polaritons For Chemistry and Quantum Simulation
Molecular vibrational polaritons are hybrid half-light, half-matter quasiparticle. This hybrid quasiparticles not only inherit properties of both photons and matters, but also processes unique new photonic and molecular phenomena, including tilting chemical potential landscapes of reactions, adding new energy transfer pathways and strong photonic interactions. Many of these developments hinge on fundamental understanding of its physical properties of molecular vibrational polaritons. Using pump probe and 2D IR spectroscopy to study vibrational-polaritons, we obtained results that advance both molecular science and photonics fields. I will discuss a few phenomena of IR molecular vibrational-polaritons: 1. Cavity-enabled intermolecular energy transfer, 2. Vibrational strong coupling accelerated barrier crossing events, and 3. Nonlinear interactions between polaritons resides in neighboring cavities. These results will have significant implications in novel infrared photonic devices, lasing, molecular quantum simulation, as well as new chemistry by tailoring potential energy landscapes.

Combining Synthetic Chemistry and Biology for Streamlining Access to Complex Molecules
2022-02-01 10:30
Abstract: By virtue of their unrivaled selectivity profiles, enzymes possess remarkable 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.

NSF Center for Integrated Catalysis Webinar Series
2022-02-01 10:30
The NSF Center for Integrated Catalysis is delighted to announce that it will be hosting a monthly webinar series. The next webinar of this series will be held on Tuesday, February 1st, 2022 at 10:30 AM. We are pleased to invite all students, postdocs, faculty, and staff.

Chem 278: Special Inorganic Chemistry Seminar - Dr. Matthew Nava
2022-02-02 16:00
“Elucidation of Reactive Species and Biological Processes Enabled by Molecular Design”

Physical Chemistry Seminar: Dr. Daniel Straus, Princeton University
2022-02-03 12:00
Structural Surprises in Inorganic and Molecular Materials
Even in some of the most heavily studied materials, a careful structural analysis can solve stubborn mysteries. The first part of my talk focuses on cesium lead iodide (CsPbI3), an inorganic halide perovskite of interest for solar energy conversion that is unstable at room temperature. I use X-ray diffraction measurements to reveal that that the Cs atom rattles within its coordination polyhedron, causing the material’s thermodynamic instability. Next, I demonstrate the remarkable emergence of chirality in the self-assembled molecular material C60(SnI4)2, despite the very high icosahedral and tetrahedral symmetry of its constituent molecules. These results demonstrate that almost any molecular, nanocrystalline, or engineered precursor can be considered when designing chiral assemblies, allowing new classes of optical devices, asymmetric catalysts, and biological sensors to be imagined.

New Base-Promoted Reductive and Oxidative Coupling Reactions
2022-02-03 16:00
Abstract: Base-catalyzed reactions typically accomplish redox neutral transformations, such as the addition of pronucleophiles to electrophiles. Our group is developing mechanistic platforms for base-promoted reductive and oxidative coupling reactions to expand the capabilities of basic chemistry. This talk will discuss the development and synthetic potential of these processes in the context of two methodologies. This includes the reductive defluorinative coupling of trifluoromethylarenes with electrophiles and the oxidative coupling of arenes with nucleophiles. Mechanistic studies will also be included to highlight the generality and future applications of these new base-promoted processes.

Chem 268 - Nicholas Graham
2022-02-04 15:30
“Identifying and decoding the function of the post-translational modifications arginine methylation and phosphorylation with proteomics”
