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Active learning environments are ideal settings to help students develop process skills such as teamwork, critical thinking, and problem solving. However, implementing active learning pedagogies where students have the opportunity to develop these skills can be challenging in large enrollment courses. With the assistance of undergraduate teaching assistants (TAs), instructors can provide an active learning experience to a large team of students during a typical “lecture” period. Most undergraduate TAs have little to no experience with facilitating active learning environments, and even less with identifying and assessing process skills. Therefore, it is important to provide training for TAs to be effective facilitators in the active learning classroom and to help students develop their process skills. Using an iterative design process, several successful strategies have been developed to help prepare undergraduate TAs to identify, assess, and provide feedback on the development of process skills in active learning classrooms. TAs report that this training was instrumental in improving their communication skills and recognizing process skills.

Assessments can provide instructors and students with valuable information regarding student’s level of knowledge and understanding, in order to improve both teaching and learning. In this study, we analyzed departmental assessment quizzes given to students at the start of Organic Chemistry 2, over an eight year period. This assessment quiz was designed to test students on core concepts from Organic Chemistry 1 that require the use of symbolic representations, such as drawing Lewis structures and using curved arrows. Using statistical analysis, it was found that students performed significantly lower than expected on the assessment quiz, and there was no significant difference in scores on the quiz over the eight years analyzed. Analysis of each individual question revealed that approximately one-third of the students made mistakes when converting a condensed formula or a chemical name to a chemical structure. For questions that involved more detailed answers such as drawing structures and showing simple ...

As part of the response to the COVID-19 pandemic in the spring 2020 semester, a large-lecture organic POGIL classroom was moved completely online. Normally the course involved daily group work that was facilitated by undergraduate teaching assistants, and these TAs would also assess student process skills such as critical thinking, information processing, teamwork, and communication. After the move to online instruction, the format of the course dramatically changed. In this communication, we describe the ways in which we attempted to maintain the basic structure of the POGIL classroom in a virtual environment. Changes to the course included the implementation of several online structures to provide students with opportunities to learn in ways that best fit their individual home situations. On the basis of survey data from the students and teaching assistants, we discuss the challenges that these two groups faced, including motivation, organization, and technological issues. We also describe how an online environment requires TAs to play a more active role in encouraging crosstalk between students than a face-to-face setting. Finally, we provide insights into how instructors can address these concerns in future online learning environments, including the use of synchronous and asynchronous activities and changes in assessment practices.

Several active-learning pedagogies involve groups of students working together to construct their own understanding of course content. In these classrooms, the instructor serves as a facilitator of learning, by interacting with every group, engaging students in discussions, answering questions, and providing formative feedback. This type of interaction can be challenging for instructors in large enrollment classes. The use of undergraduate teaching assistants (TAs) during active-learning “lecture” periods is an effective way to provide an active-learning experience to a large group of students. Most undergraduate students have little to no experience with facilitating active-learning environments. Therefore, it is important to provide a thorough TA training experience in order for TAs to be effective in an active-learning classroom. Using an iterative design process, several successful strategies were developed to help prepare undergraduate TAs to assist in facilitating a large organic chemistry active-le...

Many recent reports have called for the development of professional skills as part of a quality undergraduate experience to better prepare college graduates to enter the workforce; this preparation requires more explicit assessment of these skills in chemistry and other STEM fields. While professional skills may be part of programmatic goals, the development and assessment of these skills must largely take place as part of course experiences. However, skill development remains an implicit component of coursework that is not addressed in a meaningful way due to a lack of tools and strategies for assessing skill development and providing feedback to students. To address this need, rubrics were developed as part of the Enhancing Learning by Improving Process Skills in STEM (ELIPSS) Project to assess evidence of information processing, critical thinking, problem solving, communication, teamwork, management, and metacognition skills in student written work and group interactions. Here, we report a broad overview of how the rubrics have been implemented in multiple learning environments including detailed descriptions of two case studies. Results from faculty surveys and analysis of these case studies indicate that instructors have changed their curricula to include more explicit assessment of professional skills using a variety of instructional practices. Interviews with teaching assistants and students indicate that while the teaching assistants obtained a clearer understanding of how to assess professional skills in both written work and group interactions, the students continue to need more specific feedback in order to improve their skills.

Highly substituted cyclic β-alkoxyvinyl phosphonates underwent thermal [2+2] cycloaddition with activated ketenes to afford bicyclic phosphonates. Fragmentation of the central polarized bond of this bicyclic system occurred readily upon treatment with zinc in acetic acid, to give rise to ring expanded products. This method provides access to cycloheptane-1,3-diones substituted at the 4-position with a phosphonate group.

The reaction of ketophosphonium ylides with dimethyl acetylenedicarboxylate in aprotic solvents gave mixtures of Z and E alkene products. Under protic conditions the initial Michael adduct was protonated and gave Z and E isomers of the alkene product as well. Depending on the alkyl group of the ketoylide, different product ratios were seen.

Substituted seven and eight membered rings were formed from cyclopentanone and cyclo-hexanone via cycloadditions of pyrrolidine enamines with alkynyl phosphonates. This procedure provides straightforward access to functionalized medium sized rings that could be further manipulated in the synthesis of a number of natural products.

Alkylation of cyclic β-oxophosphonates using the ion pair extractive-phase transfer catalysis method was studied using 2-(diethoxyphosphinyl)cyclohexanone as the model compound. Unlike related phosphonic acid derivatives, the cyclic β-oxophosphonates exhibited ambident character under phase transfer conditions when dichloromethane was used as the solvent. Carbon alkylation was most effective when activated and sterically less demanding alkyl halides were utilized

Substituted seven and eight membered rings were formed from cyclopentanone and cyclo-hexanone via cycloadditions of pyrrolidine enamines with alkynyl phosphonates. This procedure provides straightforward access to functionalized medium sized rings that could be further manipulated in the synthesis of a number of natural products.

The reaction of ketophosphonium ylides with dimethyl acetylenedicarboxylate in aprotic solvents gave mixtures of Z and E alkene products. Under protic conditions the initial Michael adduct was protonated and gave Z and E isomers of the alkene product as well. Depending on the alkyl group of the ketoylide, different product ratios were seen.

Michael reaction of phosphonate stabilized anions with activated alkenes and alkynes results in 1,4-addition, diastereoselective Robinson annulation, or (n+ 2) ring enlargement reactions.

Acid halides are known to be reductively coupled with aldehydes and ketones in the presence of samarium diiodide to generate α-hydroxy ketones. Low yields coupled product are obtained due to the competitive process of tetrahydrofuran attack on the acid chloride. This competitive reaction can be avoided and yields improved by preparation of samarium diiodide in acetonitrile.

A variety of β-alkoxyvinylphosphonium bromides were prepared and reacted with sodium ethoxide and dimsyl anion to generate good yields of phosphine oxides 3 rather than the previously reported ylide 4.

Alkylation of cyclic β-oxophosphonates using the ion pair extractive-phase transfer catalysis method was studied using 2-(diethoxyphosphinyl)cyclohexanone as the model compound. Unlike related phosphonic acid derivatives, the cyclic β-oxophosphonates exhibited ambident character under phase transfer conditions when dichloromethane was used as the solvent. Carbon alkylation was most effective when activated and sterically less demanding alkyl halides were utilized

(PBr3) [7789-60-8] Br3P (MW 270.67) InChI = 1S/Br3P/c1-4(2)3 InChIKey = IPNPIHIZVLFAFP-UHFFFAOYSA-N (Cu2Br2) [7787-70-4] Br2Cu2 (MW 286.90) InChI = 1S/2BrH.2Cu/h2*1H;;/q;;2*+1/p-2 InChIKey = OFOWYKFLGFHYJJ-UHFFFAOYSA-L (Zn) [7440-66-6] Zn (MW 65.39) InChI = 1S/Zn InChIKey = HCHKCACWOHOZIP-UHFFFAOYSA-N (conversion of enediols into 1,3-dienes) Physical Data: see entries for Phosphorus(III) Bromide, Copper(I) Bromide, and Zinc.

(POCl3) [10025-87-3] Cl3OP (MW 153.32) InChI = 1S/Cl3OP/c1-5(2,3)4 InChIKey = XHXFXVLFKHQFAL-UHFFFAOYSA-N (ZnCl2) [7646-85-7] Cl2Zn (MW 136.29) InChI = 1S/2ClH.Zn/h2*1H;/q;;+2/p-2 InChIKey = JIAARYAFYJHUJI-UHFFFAOYSA-L (powerful Lewis Acid used in Friedel–Crafts reactions to prepare xanthones,1 benzophenones,2 coumarins,3 and chromanones;4 phosphorylation of alcohols5) Physical Data: see entries for Phosphorus Oxychloride and Zinc Chloride. Handling, Storage, and Precautions: in most cases, freshly fused ZnCl2 must be used for the best results. See Phosphorus Oxychloride for potential hazards.

Highly substituted cyclic β-alkoxyvinyl phosphonates underwent thermal [2+2] cycloaddition with activated ketenes to afford bicyclic phosphonates. Fragmentation of the central polarized bond of this bicyclic system occurred readily upon treatment with zinc in acetic acid, to give rise to ring expanded products. This method provides access to cycloheptane-1,3-diones substituted at the 4-position with a phosphonate group.

A critical stage in the process of developing a conceptual understanding of organic chemistry is learning to use curved arrow notation. From this stems the ability to predict reaction products and mechanisms beyond the realm of memorization. Since evaluation (i.e., testing) is known to be a key driver of student learning, it follows that a new tool for evaluating student use of curved arrows could increase understanding of curved arrows. A robust assessment of this topic can be accomplished with open-ended mechanism questions; however, there are many instances where a multiple-choice format is desirable or required (e.g., exams in very large classes, standardized exams, or in-class "clicker" questions). Our evidence suggests that typical multiple-choice questions designed to assess curved arrow use are easy to answer even without a solid conceptual understanding of organic chemistry. This article describes a new assessment technique that allows instructors to ask open-ended questions about curved arrow no...

Many students fail to develop a conceptual understanding of organic chemistry. Evidence suggests this failure goes hand-in-hand with a failure to grasp the techniques, meaning, and usefulness of curved arrow notation. Use of curved arrow notation to illustrate electrophilic addition appears to be a critical juncture in student understanding. Misconceptions arise because electrophilic addition is the first reaction where the curved arrow shows electrons from a pi bond forming a new bond that does not originate from a specific atom. This article describes a new technique (bouncing curved arrows) that addresses this stumbling block by designating which alkene carbon makes a bond to the electrophile. By removing this stumbling block and replacing it with a clear demonstration of the utility of curved arrows to describe regiochemistry of organic reactions, we encourage students to use curved arrows rather than rote memorization to deal with subsequent mechanisms. Student and faculty survey data are provided as evidence that both groups find bouncing curved arrows useful for describing electrophilic addition reactions, as well as electrophilic aromatic substitution reactions and carbocation rearrangements.

Michael reaction of phosphonate stabilized anions with activated alkenes and alkynes results in 1,4-addition, diastereoselective Robinson annulation, or (n+ 2) ring enlargement reactions.

Stereoselective rearrangement of cis-5-(4-methoxybenzyl)-spiro[5,2]-octan-4-ol cis-1 in acidified THF-90% H 2 O 2 affords 9-oxabicyclo[6.2.1]nonyl hydroperoxides 7 and 8 which are converted to medium-ring, keto-butyrolactones 2 and 3.

Ketones are readily spiroannelated by 2-chloroethyldimethyl sulfonium iodide 1 in the presence of t-butoxide anion in t-butanol. The procedure affords a simple one step -spirocyclopropanation of ketones in good yields.

Rearrangement of spiro[5,2]octan-4-ol, 1, in acidified THF-H2O2 is a selective process in which substitution occurs with retention of configuration and ring-expansion with inversion of the carbinyl center.

Synthese des composes du titre par addition de Diels Alder suivie d'une deshydrogenation aromatique