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1. Synthesis of 3‐Aminopiperidines via I(III)‐Mediated Olefin Diamination with (Hetero)aryl Nucleophiles

   https://doi.org/10.1002/adsc.202300374  

   Vazquez‐Lopez, Andres; Allen, James_E; Wengryniuk, Sarah_E (June 2023, Advanced Synthesis & Catalysis)

   Abstract 3‐Aminopiperidines are a valuable motif present in small molecule pharmaceuticals and bioactive natural products. Synthesis of these moieties via olefin diamination would be an attractive approach, however significant challenges remain with regards to both regioselectivity and exogenous nucleophile scope. Herein, we report a metal‐free olefin diamination via a “heterocyclic group transfer“ (HGT) reaction of I(III)N‐HVI reagents, giving rise to 3‐aminopiperidines with high selectivity. The HGT strategy leverages heteroarenes as oxidatively masked amine nucleophiles, giving rise to (hetero)arylonium salt products which are isolated via simple trituration and provide a versatile handle for downstream diversification. This represents only the second6‐endoselective I(III)‐mediated diamination reaction and mechanistic studies indicate ring opening of an intermediate aziridinium ion is responsible for the6‐endoselectivity. 

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2. Selenophosphoramide-catalyzed diamination and oxyamination of alkenes

   https://doi.org/10.1039/C9SC05335B  

   Tabor, John R.; Obenschain, Derek C.; Michael, Forrest E. (February 2020, Chemical Science)

   A new selenophosphoramide-catalyzed diamination of terminal- and trans -1,2-disubstituted olefins is presented. Key to the success of this transformation was the introduction of a fluoride scavenger, trimethylsilyl trifluoromethanesulfonate (TMSOTf), to prevent a competitive syn -elimination pathway, as was the use of a phosphoramide ligand on selenium to promote the desired substitution reaction. A screen of catalysts revealed that more electron-rich phosphine ligands resulted in higher yields of the desired product, with selenophosphoramides giving the optimal results. A broad range of substrates and functional groups were tolerated and yields were generally good to excellent. For ( E )-1,2-disubstituted olefins, diastereoselectivities were always high, giving exclusively anti products. The conditions were also applied to substrates bearing internal nucleophiles such as esters and carbonates, giving rise to 1,2-aminoesters and cyclic carbonates, respectively. 

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3. Catalytic, Enantioselective Diamination of Alkenes

   https://doi.org/10.1055/s-0040-1719822  

   Tao, Zhong-Lin; Denmark, Scott E. (October 2021, Synthesis)

   Abstract Enantioselective diamination of alkenes represents one of the most straightforward methods to access enantioenriched, vicinal diamines, which are not only frequently encountered in biologically active compounds, but also have broad applications in asymmetric synthesis. Although the analogous dihydroxylation of olefins is well-established, the development of enantioselective olefin diamination lags far behind. Nevertheless, several successful methods have been developed that operate by different reaction mechanisms, including a cycloaddition pathway, a two-electron redox pathway, and a radical pathway. This short review summarizes recent advances and identifies limitations, with the aim of inspiring further developments in this area. 1 Introduction 2 Cycloaddition Pathway 3 Two-Electron Redox Pathway 3.1 Pd(0)/Pd(II) Diamination 3.2 Pd(II)/Pd(IV) Diamination 3.3 I(I)/I(III) Diamination 3.4 Se(II)/Se(IV) Diamination 4 One-Electron Radical Pathway 4.1 Cu-Catalyzed Diamination 4.2 Fe-Catalyzed Diamination 5 Summary and Outlook 

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4. Diselenide-Mediated Catalytic Functionalization of Hydrophosphoryl Compounds

   https://doi.org/10.1021/acs.orglett.0c01858  

   Handoko, H.; Benslimane, Z.; Arora, P. S. (July 2020, Organic letters)

   We report a diaryldiselenide catalyst for cross-dehydrogenative nucleophilic functionalization of hydrophosphoryl compounds. The proposed organocatalytic cycle closely resembles the mechanism of the Atherton–Todd reaction, with the catalyst serving as a recyclable analogue of the halogenating agent employed in the named reaction. Phosphorus and selenium NMR studies reveal the existence of a P–Se bond intermediate, and structural analyses indicate a stereospecific reaction. 

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5. Wait Wait. No, Tell Me. Analyzing Selenium Configuration Effects on Test Flakiness

   https://doi.org/10.1109/AST.2019.000-1  

   Presler-Marshall, Kai; Horton, Eric; Heckman, Sarah; Stolee, Kathryn T. (January 2019, Proceedings of the 14th International Workshop on Automation of Software Test)

   Flaky tests are a source of frustration and uncertainty for developers. In an educational environment, flaky tests can create doubts related to software behavior and student grades, especially when the grades depend on tests passing. NC State University's junior-level software engineering course models industrial practice through team-based development and testing of new features on a large electronic health record (EHR) system, iTrust2. Students are expected to maintain and supplement an extensive suite of UI tests using Selenium WebDriver. Team builds are run on the course's continuous integration (CI) infrastructure. Students report, and we confirm, that tests that pass on one build will inexplicably fail on the next, impacting productivity and confidence in code quality and the CI system. The goal of this work is to find and fix the sources of flaky tests in iTrust2. We analyze configurations of Selenium using different underlying web browsers and timeout strategies (waits) for both test stability and runtime performance. We also consider underlying hardware and operating systems. Our results show that HtmlUnit with Thread waits provides the lowest number of test failures and best runtime on poor-performing hardware. When given more resources (e.g., more memory and a faster CPU), Google Chrome with Angular waits is less flaky and faster than HtmlUnit, especially if the browser instance is not restarted between tests. The outcomes of this research are a more stable and substantially faster teaching application and a recommendation on how to configure Selenium for applications similar to iTrust2 that run in a CI environment. 

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