Physical Sciences and Mathematics Commons^™

Synthesis Of 2-Arylpyridines By The Suzuki–Miyaura Cross-Coupling Of Pyfluor With Hetero (Aryl) Boronic Acids And Esters, Juan Rueda-Espinosa, Dewni Ramanayake, Nicholas Ball, Jennifer A. Love

Pomona Faculty Publications and Research

The Suzuki–Miyaura cross-coupling of pyridine-2-sulfonyl fluoride (PyFluor) with hetero(aryl) boronic acids and pinacol boronic esters is reported. The reactions can be performed using Pd(dppf)Cl2 as the catalyst, at temperatures between 65 and 100 °C and in the presence of water and oxygen. This transformation generates 2-arylpyridines in modest to good yields (5%–89%).

Calcium Bistriflimide-Mediated Sulfur (Vi)–Fluoride Exchange (Sufex): Mechanistic Insights Toward Instigating Catalysis, Nicholas Ball, Brian Han, Samuel R. Khasnavis, Matthew Nwerem, Michael Bertagna, O Maduka Ogba

Pomona Faculty Publications and Research

We report a mechanistic investigation of calcium bistriflimide-mediated sulfur(VI)–fluoride exchange (SuFEx) between sulfonyl fluorides and amines. We determine the likely pre-activation resting state─a calcium bistriflimide complex with ligated amines─thus allowing for corroborated calculation of the SuFEx activation barrier at ∼21 kcal/mol, compared to 21.5 ± 0.14 kcal/mol derived via kinetics experiments. Transition state analysis revealed: (1) a two-point calcium-substrate contact that activates the sulfur(VI) center and stabilizes the leaving fluoride and (2) a 1,4-diazabicyclo[2.2.2]octane additive that provides Brønsted-base activation of the nucleophilic amine. Stable Ca–F complexes upon sulfonamide formation are likely contributors to inhibited catalytic turnover, and a proof-of-principle redesign …

Sulfondiimidamides Unlocked As New S(Vi) Hubs For Synthesis And Drug Discovery, Nicholas Ball

Pomona Faculty Publications and Research

Despite their promise as drug targets, access to nitrogen-rich S(VI) compounds has been a significant synthetic challenge. In this issue of Chem, Zhang and Willis explore a new class of S(VI) compounds-sulfondiimidamides-providing robust strategies toward their synthesis, derivation, and promise as new sulfonamide bioisosteres.

The Emerging Applications Of Sulfur (Vi) Fluorides In Catalysis, Nicholas Ball, Cayo Lee, Jonathan E. Elisabeth, Nathan C. Friede, Glenn M. Sammis

Pomona Faculty Publications and Research

The past decade has witnessed remarkable growth of catalytic transformations in organic sulfur(VI) fluoride chemistry. This Perspective concentrates exclusively on foundational examples that utilize catalytic strategies to synthesize and react S(VI) fluorides. Key mechanistic studies that aim to provide insight toward future catalytic systems are emphasized.

Sufex Activation With Ca(Ntf2)2: A Unified Strategy To Access Sulfamides, Sulfamates, And Sulfonamides From S(Vi) Fluorides, Nicholas Ball, Subham Mahapatra, Cristian P. Woroch, Todd W. Butler, Sabrina N. Carneiro, Sabrina C. Kwan, Samuel R. Khasnavis, Junha Gu, Jason K. Dutra, Beth C. Vetelino, Justin Bellenger, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds.

The Principal Problem With Principal Components Regression, Heidi Margaret Artigue, Heidi Margaret Artigue

Pomona Faculty Publications and Research

Principal components regression (PCR) reduces a large number of explanatory variables down to a small number of principal components. PCR is thought to be more useful, the more numerous the potential explanatory variables. The reality is that a large number of candidate explanatory variables does not make PCR more valuable; instead, it magnifies the failings of PCR.

Sulfonamide Synthesis Via Calcium Triflimide Activation Of Sulfonyl Fluorides, Nicholas Ball, Paramita Mukherjee, Cristian P. Woroch, Leah Cleary, Mark Rusznak, Ryan W. Franzese, Matthew R. Reese, Joseph W. Tucker, John M. Humphrey, Sarah M. Etuk, Sabrina C. Kwan, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method using calcium triflimide [Ca(NTf₂)₂] as a Lewis acid to activate sulfonyl fluorides toward nucleophilic addition with amines is described. The reaction converts a wide array of sterically and electronically diverse sulfonyl fluorides and amines into the corresponding sulfonamides in good yield.

Pd-Catalyzed Conversion Of Aryl Iodides To Sulfonyl Fluorides Using So2 Surrogate Dabso And Selectfluor, Nicholas Ball, Ariana L. Tribby, Ismerai Rodríguez, Shamira Shariffudin

Pomona Faculty Publications and Research

A one-pot Pd-catalyzed conversion of aryl iodide to aryl sulfonyl fluorides using DABSO and Selectfluor has been developed generating aryl sulfonyl fluorides in good to excellent yields. The reaction results in the generation of electronically and sterically diverse sulfonyl fluorides. Additionally, sulfonyl fluorides can be converted to aryl sulfonamides and sulfonic esters using Cs₂CO₃ under mild conditions.

The Pinchot Wire: Private Cash, Public Lands - Why The Katahdin Woods And Waters National Monument Matters, Char Miller

Pomona Faculty Publications and Research

Here’s how President Obama celebrated the National Park Service’s 100th birthday: with the stroke of his pen, he established the Katahdin Woods and Waters National Monument in Maine, one of the most innovative initiatives in U.S. environmental history. That’s because the 87,500-acre park, which encompasses some of the Pine Tree State’s most remarkable forests and waterways, is a gift of the Quimby family and comes with a $40 million endowment, a private-public partnership without parallel.

Embers, Char Miller

Pomona Faculty Publications and Research

After living in Southern California for nine years, I should be used to fire season—and the fact that there is something called fire season—but I’m not.

My wife and I moved to the Southland in late summer 2007, and within the month we saw some of the region’s most horrific firestorms consume vast stretches of chaparral-cloaked foothills, deep canyons filled with alder and oak and, at higher elevations, thick stands of pine and cedar.

The Problems Of Contemporariness And Voice: Review Of Literacy & Mathematics: A Contemporary Approach To Quantitative Literacy By Jay P. Abramson And Matthew A. Isom (2005), Gizem Karaali

Pomona Faculty Publications and Research

The book under review covers the traditional content of a typical mathematical literacy text. After a brief overview of the book contents, the review then focuses on two specific challenges that QL textbooks have to meet: the timeliness of the contexts used and the subjective author voice that inevitably colors any contextualized discussion. Both issues noticeably arise in the text reviewed. Nonetheless instructors may find it a helpful resource.

One View: Fire Fuels Regeneration In Eastern Sierra, Char Miller

Pomona Faculty Publications and Research

Sometimes it’s the small things that can best tell big stories.

Like the Marina Fire, which currently has burned a modest 800 acres to the north of Lee Vining, threatened but did not burn any structures, and whose greatest disruption has been periodically to shut down US 395. It hardly seems worth much attention.

Dead Trees Don’T Mean Catastrophe For California, Char Miller

Pomona Faculty Publications and Research

Nature knows what it’s doing. You’d never know that, though, from the panicked reaction to news that 66 million trees in California have died since 2005, including 26 million said to have perished just in the last few months.

The Erskine Fire And Public-Lands Management In The American West, Char Miller

Pomona Faculty Publications and Research

The Erskine Fire is big, fast and dangerous. Its power is evident in the tragic loss of life, the incineration of an estimated 150 structures and its rapid growth — more than 36,000 acres burned in its first 30 hours.

Fire Inevitable, Despite Attempts To Tame Chaparral, Char Miller

Pomona Faculty Publications and Research

You didn’t need to fly into Ontario International Airport this past week to know that Southern California’s fire season had begun. But the view from 10,000 feet offered a unique perspective on how wildfires impact the region.

Math Education: A Messy Problem, Gizem Karaali

Pomona Faculty Publications and Research

The current state of math education in America is certainly not ideal, writes Gizem Karaali, but mathematicians, researchers, policy makers and others are working on it -- and it is definitely a problem worth working on.

Rethinking La's Nature Through German Eyes, Char Miller

Pomona Faculty Publications and Research

Los Angeles might be more than 5700 miles from Berlin as a crow (or Luftansa) flies, but German culture—and most notably its varied perceptions of nature—have strongly influenced how those living in the Southland experience their environs.

Oft in the negative, to judge from the enduring legacy of Bertold Brecht’s sharp commentary about the City of Angeles in which he sheltered during the ravages of World War II. “They have nature here,” he jotted down in his diary in August 1941, and as “everything is so artificial, they even have an exaggerated feeling for nature, which becomes alienated.”

Rethinking: Wind, Wende, Wandel, Friederike Von Schwerin-High

Pomona Faculty Publications and Research

No abstract provided.

Umdenken: Von Der Natur Lernen (Rethinking: Learning From Nature): Some Personal Thoughts On The Goethe Institute Traveling Exhibition, Hans J. Rindisbacher

Pomona Faculty Publications and Research

No abstract provided.

Collaboration And Creativity In Southern Califonia: An Offering, Gizem Karaali, Ami Radunskaya

Pomona Faculty Publications and Research

WiMSoCal (Women in Math in Southern California) is a regional conference in its ninth incarnation. The conference is the result of the efforts of Professor Cymra Haskell (USC) to create a supportive local community for women mathematicians. At our first meeting in 2007, a confluence of Ami’s EDGE regional cluster and Cymra’s WISE group at USC, we socialized, got to know each other and brainstormed about what we, as a group, would like to see happen. It was clear that our younger colleagues wanted to meet as mathematicians, sharing intellectual ideas as well as anecdotes from the trenches.

The Power Of Two: Two Tips For Mathematicians, Gizem Karaali

Pomona Faculty Publications and Research

This post is about two great tips involving the number 2 that I learned along the way. They will perhaps not double your happiness or fortune, but I promise you that you will not regret it if you do decide to take them along for the ride.

Review: On Complex Symmetric Toeplitz Operators, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Review: On Rank One Perturbations Of Complex Symmetric Operators, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Review: A C*-Algebra Approach To Complex Symmetric Operators, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

Malheur Occupation In Oregon: Whose Land Is It Really?, Char Miller

Pomona Faculty Publications and Research

The Malheur National Wildlife Refuge, a 187,757-acre haven for greater sandhill cranes and other native birds in eastern Oregon, is usually a pretty peaceful place. But its calm was shattered on Saturday, January 2 when Ammon Bundy and a group of armed men broke into and occupied a number of federal buildings on the refuge, vowing to fight should the government try to arrest them. Their insurrectionary goal appears to be, simply put, to destroy the national system of public lands – our forests, parks and refuges – that was developed in the late 19th century to conserve these …

Review: Transitivity And Bundle Shifts, Stephan Ramon Garcia

Pomona Faculty Publications and Research

No abstract provided.

On The Similarity Of Ab And Ba For Normal And Other Matrices, Stephan Ramon Garcia, David Sherman, Gary Weiss

Pomona Faculty Publications and Research

It is known that AB and BA are similar when A and B are Hermitian matrices. In this note we answer a question of F. Zhang by demonstrating that similarity can fail if A is Hermitian and B is normal. Perhaps surprisingly, similarity does hold when A is positive semidefinite and B is normal.

What's In A Name? A Critical Review Of Definitions Of Quantitative Literacy, Numeracy, And Quantitative Reasoning, Gizem Karaali, Edwin H Villafane Hernandez '18, Jeremy Alexander Taylor '18

Pomona Faculty Publications and Research

This article aims to bring together various threads in the eclectic literature that make up the scholarship around the theme of Quantitative Literacy. In investigating the meanings of terms like "quantitative literacy," "quantitative reasoning," and "numeracy," we seek common ground, common themes, common goals and aspirations of a community of practitioners. A decade ago, these terms were relatively new in the public sphere; today policy makers and accrediting agencies are routinely inserting them into general education conversations. Having good, representative, and perhaps even compact and easily digestible definitions of these terms might come in handy in public relations contexts as …

Visual Properties Of Generalized Kloosterman Sums, Paula Burkhardt '16, Alice Zhuo-Yu Chan '14, Gabriel Currier '16, Stephan Ramon Garcia, Florian Luca, Hong Suh '16

Pomona Faculty Publications and Research

For a positive integer m and a subgroup A of the unit group (Z/mZ)^x, the corresponding generalized Kloosterman sum is the function K(a, b, m, A) = Σ_uEA e(au+bu^-1/m). Unlike classical Kloosterman sums, which are real valued, generalized Kloosterman sums display a surprising array of visual features when their values are plotted in the complex plane. In a variety of instances, we identify the precise number-theoretic conditions that give rise to particular phenomena.

Lattices From Hermitian Function Fields, Albrecht Böttcher, Lenny Fukshansky, Stephan Ramon Garcia, Hiren Maharaj

Pomona Faculty Publications and Research

We consider the well-known Rosenbloom-Tsfasman function field lattices in the special case of Hermitian function fields. We show that in this case the resulting lattices are generated by their minimal vectors, provide an estimate on the total number of minimal vectors, and derive properties of the automorphism groups of these lattices. Our study continues previous investigations of lattices coming from elliptic curves and finite Abelian groups. The lattices we are faced with here are more subtle than those considered previously, and the proofs of the main results require the replacement of the existing linear algebra approaches by deep results of …