Timothy Beng

CWU Courses

Organic Chemistry Lecture
Organic Chemistry Lab
Current Topics in Chemistry-Chemistry of Heterocycles

Education

o    2011 – PhD University of Arkansas

o    2004 - MS, East Tennessee State University

o    2001 - BS, University of Buea

Research Interests

Development of Synthetic Methodology for Efficient and Expedient Functionalization of Nitrogen and Oxygen-Containing Heterocycles for Eventual Application in Natural and Unnatural Product Synthesis

Publications: 

• Timothy K. Beng, Claire Borg, and Morgan J. Rodriguez; “Contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids for the flexible and stereocontrolled synthesis of fused lactam-halolactones”, RSC Advances, 2022, 12, 28685 – 28691.
  Highlight: The site-selective, efficient, and stereocontrolled synthesis of halogenated fused g-lactone-lactams has been accomplished through the catalytic and contra-thermodynamic halolactonization of readily available allylic lactam acids. The innate tendency of these lactam-tethered-5-aryl-4(E)-pentenoic acids to undergo 6-endo cyclization is overridden in favor of 5- exo cyclization by catalyst- and solvent-controlled reactivity.
• Timothy K. Beng, Mckenna Sax, and Claire Borg; “Serendipitous synthesis of 2-alkenyl- and 2-aryl-4-thiazolidinones using dithiodiglycolic anhydride”, New J. Chem., 2022, 46, 18505 – 18511.
  Highlight: The strategic deployment of dithiodiglycolic anhydride as an alternative to mercaptoacetic acid, a liquid with a pungent smell, has led to a modular and practical synthesis of benzylic and allylic 4-thiazolidinones, by engaging the aforementioned anhydride in a formal [3+2]-cycloaddition with aryl aldimines or 1,3-azadienes. The scalable nature of the reactions offers the opportunity for post-modification by incorporation of motifs (sulfoxides, sulfones, and epoxides) with either known pharmaceutical value or that permit subsequent conversion to medicinally relevant entities.
• Timothy K. Beng, Morgan J. Rodriguez, and Claire Borg; “Stereocontrolled access to δ-lactone-fused-γ-lactams bearing angular benzylic quaternary stereocenters”, RSC Advances, 2022, 12, 17617 – 17620.
  Highlight: The diastereoselective and scalable synthesis of halogenated fused γ-lactam-δ-lactones has been accomplished, through the deployment of γ-lactam-tethered alkenoic acids in a catalytic halolactonization protocol. The sp3-rich fused γ-lactam-δ-lactones bear medicinally relevant quaternary and contiguous stereocenters. We anticipate that this practical, cost-effective, and catalytic strategy would undeniably expand the 3D-structural space for the discovery of new γ,δ-lactam-lactones with medicinal value.
• Jorge Garcia, Jane Eichwald, Jayme Zesiger, and Timothy K. Beng; “Leveraging the 1,3-azadiene-anhydride reaction for the synthesis of functionalized piperidines bearing up to five contiguous stereocenters”, RSC Advances, 2022, 12, 309 – 318.
  Highlight: The modular construction of functionalized 2-oxopiperidines bearing at least three contiguous stereocenters has been accomplished. The criteria of efficiency, versatility, and pot-atom-step economy are of paramount importance in modern day synthetic chemistry and these studies have met these benchmarks. We anticipate that the aforementioned merits will endear this methodology to both the synthesis and medicinal chemistry communities.
• Jorge Garcia, Jane Eichwald, Jayme Zesiger, and Timothy K. Beng; “Leveraging the 1,3-azadiene-anhydride reaction for the synthesis of functionalized piperidines bearing up to five contiguous stereocenters”, RSC Advances, 2022, 12, 309 - 318.  
• Timothy K. Beng, Abdikani Omar Farah, and Victoria Shearer; “Modular synthesis and transition metal-free alkynylation/alkenylation of Castagnoli-Cushman-derived N,O- and N,S-heterocyclic vinyl chlorides”, RSC Advances, 2020, 10, 37153 - 37160
• Timothy K. Beng, Jorge Garcia, Meagan Smith, and Alexis O. Orellana; “Skeletal remodelling of α-substituted cyclic eneformamides to α-ketonyl cyclic amines”, New J. Chem., 2020, 44, 15337 - 15340.  
• Abdikani Omar Farah, Muhannad Rabah, and Timothy K. Beng; “Transition metal-free domino acyl substitution/Michael addition of alkenyl Grignard reagents to lactam esters: Synthesis of lactam-bearing homoallylic ketones”, RSC Advances, 2020, 10, 22454 - 22459.
• Timothy K. Beng, Victoria Shearer, Rachel Davey, and Ivianne Redman; “Site-selective, catalytic, and diastereoselective sp3 C–H hydroxylation and alkoxylation of vicinally functionalized lactams”, RSC Advances, 2020, 10, 20264 - 20271.
• Timothy K. Beng and Abdikani Omar Farah; “Modular access to formamide-tethered α-halo ynones via the deconstructive oxo-halogenation of readily available α-alkynyl eneformamides”, Tetrahedron Lett., 2020, 61, 151821.
• Timothy K. Beng and Antonio Moreno; “Copper-catalyzed alkenylation of novel N-iodoarylated allylic ketopiperazinonates with unactivated alkenes”, New Journal of Chemistry, 2020, 44, 4257 - 4261.
• Timothy K. Beng and Antonio Moreno; “Catalytic, selective, and stereocontrolled construction of C4 quaternary and homobenzylic dihydroisoquinolones by sp3 C–H benzylation”, RSC Advances, 2020, 10, 8805 - 8809.
• Antonio Moreno and Timothy K. Beng; “Direct access to vicinally functionalized and N-trifluoroacetylated (bicyclic) ketopiperazines using a readily affordable N-heterocyclic anhydride”, Organic and Biomolecular Chemistry, 2020, 18, 1577.
• Timothy K. Beng, Spencer Langevin, Abdikani Omar Farah, Joshua Goodsell, and Katie Wyatt; “One shot access to isoquinolone and (hetero)izidinone architectures using cyclic α-chloroeneformamides and cyclic anhydrides”, New Journal of Chemistry. 2019, 43, 5282 - 5286.
• Timothy K. Beng and Francine Wanjiku; “Iridium-catalyzed α-alkynylation of cyclic nonaromatic eneformamides: Application to the synthesis of azapolycyclic architectures”, New Journal of Chemistry, 2019, 43, 4664 - 4668.
• Timothy K. Beng, Megan Bauder, Morgan J. Rodriguez, and Antonio Moreno; “Copper-catalyzed regioselective dehydrogenative alkoxylation of morpholinonyl alkenols: application to the synthesis of spirotricyclic dihydropyrans and of trans-fused bicyclic morpholines”, New Journal of Chemistry. 2018, 42, 16451, DOI: 10.1039/C8NJ03890B.
• Abdikani Omar Farah, Ryan Archibald, Morgan J. Rodriguez, Antonio Moreno, Blaise Dondji, and Timothy K. Beng; “Flexible access to 2,3,5,6-tetrasubstituted dehydropiperidines by Ni- or Co-catalyzed site-selective cross-coupling using Vilsmeier-Haack-derived α-chloro-β-formyltetrahydropyridines”, Tetrahedron Lett. 2018, 59, 3495.
• Katie Hovenkotter, Hannah Braunstein, Spencer Langevin and Timothy K. Beng; “Expedient and modular access to 2-azabicyclic architectures by iron-catalyzed dehydrative coupling of alcohol-bearing allylic lactams”, Organic and Biomolecular Chemistry, 2017, 15, 1217
• Hannah Braunstein, Spencer Langevin, Monique Khim, Jonathan Adamson, Katie Hovenkotter, Lindsey Kotlarz, Brandon Mansker and Timothy K. Beng; “Modular access to vicinally functionalized allylic (thio)morpholinonates and piperidinonates by substrate-controlled annulation of 1,3-azadienes with hexacyclic anhydrides”, Organic and Biomolecular Chemistry, 2016, 14; 8864
• Timothy K. Beng, Spencer Langevin, Hannah Braunstein, and Monique Khim; “Regiocontrolled synthesis of (hetero)aryl and alkenyl dehydropyrrolidines, dehydropiperidines and azepenes by Ru-catalyzed, heteroatom-directed α-C-H activation/cross-coupling of cyclic enamides with boronic acids”, Organic and Biomolecular Chemistry, 2016, 14; 830
• Timothy K. Beng, Nathan Fox, Daniel P. Bassler, Amir Alwali, Kayla Sincavage, and Ann Wen V. Silaire; “Trapping of carbolithiation-derived tertiary benzylic α-lithio piperidines with carbon electrophiles: Controlling the formation of α-amino quaternary and vicinal stereocenters”, Organic and Biomolecular Chemistry, 2015, 13, 8647
• Timothy K. Beng, Ann Wen V. Silaire, Amir Alwali, and Daniel P. Bassler; “One-shot access to α,β-difunctionalized azepenes and dehydropiperidines by reductive cross-coupling of α-selenonyl-β-selenyl enamides with organic bromides”, Organic and Biomolecular Chemistry, 2015, 13, 7915
• Timothy K. Beng, Kayla Sincavage, Ann Wen V. Silaire, Amir Alwali, Daniel P. Bassler, Laura Spence, and Oliver Beale; “Direct access to functionalized benzotropones, azepanes and piperidines by reductive cross-coupling of α-bromo enones with α-bromo enamides”, Organic and Biomolecular Chemistry, 2015, 13, 5349
• Daniel P. Bassler, Amir Alwali, Laura Spence, Oliver Beale, and Timothy K. Beng; “Cobalt-Catalyzed Arylation and Alkenylation of Alpha-Bromo Eneformamides and Enecarbamates by Cross-Coupling with Organic Bromides: Application to the Synthesis of Functionalized Piperidines and Azepanes”, Journal of Organometallic Chemistry, 2015, 780, 6-12
• Daniel P. Bassler, Laura Spence, Amir Alwali, Oliver Beale, and Timothy K. Beng; "Expedient Access to α,β-Difunctionalized Azepenes using α-Chloro Eneformamides: Application to the One-Pot Synthesis of 2-Benzazepanes", Organic and Biomolecular Chemistry, 2015, 13, 2285.
• Timothy K. Beng and Nathan Fox, " Diastereoselective Synthesis of α,α,α’-Trisubstituted Pyrrolidines and Piperidines by Directed Sequential Lithiation/Alkylation", Tetrahedron Lett. 2015, 56, 119.
• Timothy K. Beng and Daniel P. Bassler, "Vicinal Difunctionalization of Dehydropiperidines using α-Halo Eneformamides", Tetrahedron Lett. 2014, 55, 6662.
• Timothy K. Beng, Hironori Takeuchi, Manuel Weber, and Richmond Sarpong; “Stereocontrolled synthesis of vicinally functionalized piperidines by nucleophilic β-addition of alkyllithiums to α-aryl substituted piperidine enecarbamates”, Chem. Commun., 2015, 61, 7653
• Timothy K. Beng, Sidney M. Wilkerson-Hill, and Richmond Sarpong, "Direct Access to Functionalized Azepanes by Cross-Coupling with Alpha-Halo Eneformamides", Org. Lett. 2014, 16, 916. Corrigendum: Org. Lett. 2014, 16, 3170
• Timothy K. Beng, Jin Sun Woo, and Robert E. Gawley, Synthetic Applications and Inversion Dynamics of Configurationally Stable 2-Lithio-2-aryl-Pyrrolidines and -Piperidines, J. Am. Chem. Soc. 2012, 134, 14764-14771
• Timothy K. Beng, William S. Tyree, Trent Parker, Chicheung Su, Paul G. Williard, and Robert E. Gawley, “Dynamics of Catalytic Resolution of 2-Lithio-N-Boc-piperidine by Ligand Exchange”, J. Am. Chem. Soc. 2012, 134, 16845-16855
• Timothy K. Beng and Robert E. Gawley, "Catalytic Dynamic Resolution Applied to the Synthesis of 2,6-Disubstituted Piperidines: Preparation of (+)-Lupetidine and (–)-Epidihydropinidine”, Heterocycles 2012, 24, 697. Highlighted in ChemInform 2012, 43, issue 21
• Timothy K. Beng and Robert E. Gawley, "Application of Catalytic Dynamic Resolution of N-Boc-2-lithiopiperidine to the Asymmetric Synthesis of 2-Aryl and 2-Vinyl Piperidines", Org. Lett. 2011, 13, 394-397. Highlighted in Synfacts 2011, 4, 0430. Reviewed extensively in Chemical Reviews 2015, DOI: 10.1021/acs.chemrev.5b00162.
• Timothy K. Beng and Robert E. Gawley," Highly Enantioselective Catalytic Dynamic Resolution of N-Boc-2-lithiopiperidine: Synthesis of (R)-(+)-Pipecolic acid, (S)-(–)-Coniine, (S)-(+)-Pelletierine, (+)-β-Conhydrine, (S)-(–)-Ropivacaine, and Formal Synthesis of (–)-Lasubine II and (+)-Cermizine C", J. Am. Chem. Soc. 2010, 132, 12216-12217. Highlighted in Synfacts 2010, 12, 1328. Reviewed extensively in Chemical Reviews 2015, DOI: 10.1021/acs.chemrev.5b00162
• Iain Coldham, Daniele Leonori, Timothy K. Beng, and Robert E. Gawley, “The barrier to enantiomerization and dynamic resolution of N-Boc-2-lithiopiperidine and the effect of TMEDA”, Chem. Commun., 2009, 5239 – 5241; Corrigendum with correct enthalpy and entropy values: 2010, 9267−9268.
• Timothy K. Beng, Taher I. Yousaf, Iain Coldham, and Robert E. Gawley, "Enantiomerization Dynamics and a Catalytic Dynamic Resolution of N-Trimethylallyl-2-lithiopyrrolidine", J. Am. Chem. Soc. 2009, 131, 6908-6909. Reviewed extensively in Chem. Eur. J. 2012, 18, 10092-10142

Selected Honors and Awards

• Research Mini Grant, Committee of Faculty Scholarship, Susquehanna University       2014 – current
• Research Funds, Department of Chemistry, Susquehanna University                               2014 – current
• Ruth L. Kirschstein National Research Service Award (F32 Postdoctoral Fellowship) 2012 – 2014
• Invited Speaker, RSC 21^st Heterocyclic & Synthetic Group Symposium, Grasmere        2013
• Two Golden Tusk Awards for Excellence in Teaching, University of Arkansas    2012
• NIH Travel Grant, Pacifichem, Honululu, Hawaii            2010        
• NSF Travel Grant, Gordon Research Conference, Salve Regina, Newport, Rhode Island     2010
• University of Arkansas Travel Grant, 62^nd Regional ACS Meeting, San Francisco         2010
• Teaching & Research Assistantships, University of Arkansas                                              2007 – 2011
• Margaret Sells Scholarship, East Tennessee State University         2003
• Graduate Fellowship, East Tennessee State University                                                        2003 – 2004