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Cohen RD, Wood JS, Lam YH, Buevich AV, Sherer EC, Reibarkh M, Williamson RT, Martin GE. DELTA50: A Highly Accurate Database of Experimental 1H and 13C NMR Chemical Shifts Applied to DFT Benchmarking. Molecules 2023; 28:molecules28062449. [PMID: 36985422 PMCID: PMC10051451 DOI: 10.3390/molecules28062449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/23/2023] [Accepted: 02/28/2023] [Indexed: 03/30/2023] Open
Abstract
Density functional theory (DFT) benchmark studies of 1H and 13C NMR chemical shifts often yield differing conclusions, likely due to non-optimal test molecules and non-standardized data acquisition. To address this issue, we carefully selected and measured 1H and 13C NMR chemical shifts for 50 structurally diverse small organic molecules containing atoms from only the first two rows of the periodic table. Our NMR dataset, DELTA50, was used to calculate linear scaling factors and to evaluate the accuracy of 73 density functionals, 40 basis sets, 3 solvent models, and 3 gauge-referencing schemes. The best performing DFT methodologies for 1H and 13C NMR chemical shift predictions were WP04/6-311++G(2d,p) and ωB97X-D/def2-SVP, respectively, when combined with the polarizable continuum solvent model (PCM) and gauge-independent atomic orbital (GIAO) method. Geometries should be optimized at the B3LYP-D3/6-311G(d,p) level including the PCM solvent model for the best accuracy. Predictions of 20 organic compounds and natural products from a separate probe set had root-mean-square deviations (RMSD) of 0.07 to 0.19 for 1H and 0.5 to 2.9 for 13C. Maximum deviations were less than 0.5 and 6.5 ppm for 1H and 13C, respectively.
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Affiliation(s)
- Ryan D Cohen
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
| | - Jared S Wood
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28409, USA
| | - Yu-Hong Lam
- Department of Computational and Structural Chemistry, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Alexei V Buevich
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Edward C Sherer
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - Mikhail Reibarkh
- Analytical Research and Development, Merck & Co., Inc., Rahway, NJ 07065, USA
| | - R Thomas Williamson
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28409, USA
| | - Gary E Martin
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
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Deprez NR, Clausen DJ, Yan JX, Peng F, Zhang S, Kong J, Bai Y. Selective Electrochemical Oxidation of Functionalized Pyrrolidines. Org Lett 2021; 23:8834-8837. [PMID: 34730984 DOI: 10.1021/acs.orglett.1c03338] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A method for the selective electrochemical aminoxyl-mediated Shono-type oxidation of pyrrolidines to pyrrolidinones is described. These transformations show the high selectivity and functional group compatibility. This chemistry also demonstrates the use of an operationally simple ElectraSyn 2.0 and cost-effective stainless-steel electrode for the electrochemical oxidation of functionalized pyrrolidines.
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Affiliation(s)
- Nicholas R Deprez
- Process Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Dane J Clausen
- Discovery Chemistry, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Jia-Xuan Yan
- Analytical Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Feng Peng
- Process Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Shaoguang Zhang
- Process Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Jongrock Kong
- Process Research and Development, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Yanguang Bai
- WuXi AppTec (Tianjin) Co. Ltd., Tianjin 300457, China
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Dallaston MA, Bettencourt CJ, Chow S, Gebhardt J, Spangler J, Johnston MR, Wall C, Brusnahan JS, Williams CM. Ranking Oxidant Sensitiveness: A Guide for Synthetic Utility. Chemistry 2019; 25:9614-9618. [DOI: 10.1002/chem.201902036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Indexed: 01/17/2023]
Affiliation(s)
- Madeleine A. Dallaston
- School of Chemistry and Molecular BiosciencesUniversity of Queensland Brisbane 4072 Australia
| | | | - Sharon Chow
- School of Chemistry and Molecular BiosciencesUniversity of Queensland Brisbane 4072 Australia
| | - Joshua Gebhardt
- Flinders Institute for Nanoscale Science and TechnologyCollege of Science and EngineeringFlinders University South Australia 5042 Australia
| | - Jordan Spangler
- Flinders Institute for Nanoscale Science and TechnologyCollege of Science and EngineeringFlinders University South Australia 5042 Australia
| | - Martin R. Johnston
- Flinders Institute for Nanoscale Science and TechnologyCollege of Science and EngineeringFlinders University South Australia 5042 Australia
| | - Craig Wall
- Defence Science and Technology Group Edinburgh South Australia 5111 Australia
| | - Jason S. Brusnahan
- Defence Science and Technology Group Edinburgh South Australia 5111 Australia
| | - Craig M. Williams
- School of Chemistry and Molecular BiosciencesUniversity of Queensland Brisbane 4072 Australia
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