Highly diastereoselective synthesis of substituted pyrrolidines using a sequence of azomethine ylide cycloaddition and nucleophilic cyclization

Abstract: Although cycloadditions of azomethine ylides usually give mixtures of endo/exo adducts, we successfully tuned the mechanistic path of a new reaction cascade to afford substituted pyrrolidines in high yields and diastereomeric purity. This was achieved by forcing the demetalation of tin- or silicon-substituted iminium ions, followed by azomethine ylide cycloaddition and nucleophilic cyclization. Structural complexity is thus built rapidly in a fully controlled one-pot reaction cascade

BERKREASI MEMBUAT KERAJINAN TANGAN SEKALIGUS MENGURANGI SAMPAH BOTOL PLASTIK

Berbagai peristiwa banjir di Kota dan Kabupaten Jayapura pada Februari dan Maret tahun ini telah menyebabkan sejumlah kerugian. Sejumlah kerugian tersebut berupa harta benda, rumah hingga nyawa. Peristiwa banjir ini dicoba dicarikan solusinya setidaknya dengan mengurangi kemungkinan terjadinya banjir kembali. Dengan berbagai penyebab banjir yang ada, kegiatan pengabdian pada masyarakat ini lebih fokus pada sampah botol plastik yang dibuat oleh manusia. Berbagai sampah botol plastik ini diolah dan dijadikan kerajinan tangan yang berguna sekaligus mengurangi jumlah sampah yang ada khususnya sampah botol plastik. Lokasi kegiatan pada masyarakat ini dilakukan di kompleks Perumahan Umum Polda Bhayangkara Kampung Waena Distrik Heram. Kesimpulan pertama adalah telah dilakukan kegiatan pengabdian pada masyarakat di wilayah kompleks Perumahan Umum Polda Bhayangkara Kampung Waena Distrik Heram selama 6 hari dari akhir Juni hingga awal Juli 2019. Kesimpulan kedua adalah dilakukan kegiatan pengabdian melalui kerajinan tangan ini diikuti oleh para peserta di wilayah kompleks Perumahan Umum Polda Bhayangkara Kampung Waena Distrik Heram ini. Kesimpulan ketiga adalah dengan telah dilakukannya kegiatan pada masyarakat ini setidaknya telah menggunakan sejumlah bahan dari sampah botol minuman plastik yang dikumpulkan dari wilayah sekitar kompleks Perumahan Umum Polda Bhayangkara Kampung Waena Distrik Heram. Dengan menggunakan sejumlah sampah botol minuman plastik yang beraneka ragam bentuk dan warnanya maka melalui kegiatan pengabdian pada masyarakat ini telah berupaya dalam mengurangi volume sampah di sekitar wilayah perumahan ini. Kata Kunci : Kreasi, Kerajinan Tangan, Botol Plasti

Anti-tumor Activity of N4 [(E)-1-(2-hydroxyphenyl) Methylidene], N4-[(E)-2-Phenylethylidene], N4 [(E,2E)-3-Phenyl-2-propenylidene], and N4 [(E)ethylidene] Isonicotinohydrazide on K562 and Jurkat Cell Lines

Using the water eliminated mechanism, reactions of 4-pyridinecarboxylic acid hydrazide and salicylaldehyde, benzaldehyde, cinnamaldehyde, and formaldehyde afforded the corresponding N4[(E)-1-(2-hydroxyphenyl) methylidene] (NHPM), N4-[(E)-2-phenylethylidene] (NPI), N4[(E,2E)-3-phenyl-2-propenylidene] (NPPI), and N4[(E) ethylidene] (NEI) isonicotinohydrazide, in high yields, after several minutes, as reported. These new compounds have shown antitumor activity against two kinds of cancer cells, which are K562 (human chronic myeloid leukemia) and Jurkat (human T lymphocyte carcinoma)

One-Pot Acid-Catalyzed Ring-Opening/Cyclization/Oxidation of Aziridines with N-Tosylhydrazones: Access to 1,2,4-Triazines

A new, three-step, telescoped reaction sequence for the regioselective conversion of N-tosyl hydrazones and aziridines to 3,6-disubstituted and 3,5,6-trisubstituted 1,2,4-triazines is described. The process involves an efficient nucleophilic ring opening of the aziridine, giving access to a wide range of aminohydrazones, isolated with excellent yields. A “one-pot” procedure, combining the ring opening with a cyclization and an oxidation step, allows the preparation of diversified triazines in good yields.This work was supported by a postdoctoral fellowship from Pfizer (L.C.) and EPSRC Grant Nos. EP/K009494/1 and EP/M004120/1 (S.V.L.). We also thank Dr. Andrew D. Bond for conducting X-ray crystallographic analysis

Building Interdisciplinary Teams in Emergency Care to Respond to National Emergencies: Addressing the Opioid Epidemic

This study responds to the gap in knowledge in translating team members’ interdisciplinary knowledge to address wicked problems. We use qualitative methodology to understand the team-building process and response to the opioid epidemic in emergency care. We collected data through direct observation of nine health system science researchers and thought leaders as they performed in team-building activities and semi-structured interviews. The cultural exchange framework informed our selection and assessment of team-building activities, and the science of team science (SciTS) framework informed our understanding of promoting interdisciplinary collaborations. We identified six themes representing three areas: (1) Knowledge Building and Strategy Development (need for interdisciplinary understanding of substance abuse and mental health in the emergency department (ED); interdisciplinary approaches to fight the opioid epidemic in the ED); (2) Team Demographics and Collaboration (prescribing and collaboration; the role of interdisciplinary team composition and effectiveness in the ED); and (3) Identity and Relationship Building (role of professional identity in contributing to interdisciplinary research; building effective organizational relationships in the ED). Members’ personal and professional connections are fundamental for developing nuanced interdisciplinary strategies to respond to the opioid epidemic in the ED. We discuss implications for strategies that promote team building and improve treatment practices

Carbenic nitrile imines: Properties and reactivity

Structures and properties of nitrile imines were investigated computationally at B3LYP and CCSD(T) levels. Whereas NBO analysis at the B3LYP DFT level invariably predicts a propargylic electronic structure, CCSD(T) calculations permit a clear distinction between propargylic, allenic, and carbenic structures. Nitrile imines with strong IR absorptions above ca. 2150 cm-1 have propargylic structures with a CN triple bond (RCNNSiMe 3 and R2BCNNBR2), and those with IR absorptions below ca. 2150 cm-1 are allenic (HCNNH, PhCNNH, and HCNNPh). Nitrile imines lacking significant cumulenic IR absorptions at 1900-2200 cm -1 are carbenic (R-(C:)-N=N-R′). Electronegative but lone pair-donating groups NR2, OR, and F stabilize the carbenic form of nitrile imines in the same way they stabilize "normal" singlet carbenes, including N-heterocyclic carbenes. NBO analyses at the CCSD(T) level confirm the classification into propargylic, allenic, and carbenic reactivity types. Carbenic nitrile imines are predicted to form azoketenes 21 with CO, to form [2+2] and [2+4] cycloadducts and borane adducts, and to cyclize to 1H-diazirenes of the type 24 in mildly exothermic reactions with activation energies in the range 29-38 kcal/mol. Such reactions will be readily accessible photochemically and thermally, e.g., under the conditions of matrix photolysis and flash vacuum thermolysis

Expanding Stereochemical and Skeletal Diversity Using Petasis Reactions and 1,3-Dipolar Cycloadditions

A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis.Chemistry and Chemical Biolog