Chiral Separations and Stereochemical Elucidation

Quezia Bezerra Cass, PhD, is a Full Professor of Chemistry at Universidade Federal de São Carlos, São Carlos, SP, Brazil. Maria Elizabeth Tiritan, PhD, is an Assistant Professor of Organic Chemistry at Universidade do Porto, Porto, Portugal. João Marcos Batista Junior, PhD, is an Assistant Professor of Chemistry at Universidade Federal de São Paulo, São José dos Campos, SP, Brazil. Juliana Cristina Barreiro, PhD, is a Researcher in Chemistry at Universidade de São Paulo, São Carlos, SP, Brazil.

• List of Contributors xvPreface xixPart I Fundamentals of Chiral Separation 11 Chiral Separation by LC 3Juliana Cristina Barreiro and Quezia Bezerra Cass1.1 Introduction 31.2 Workflow for LC Chiral Method Development 71.3 New Column Technologies 91.4 Selected Examples of Fast Separation 121.5 Chiral 2D- LC 141.5.1 LC–LC and mLC–LC 141.5.2 LC × LC and sLC × LC 171.6 Future and Perspectives 19References 202 Chiral Separation by GC 27Oliver Trapp2.1 Introduction 272.2 Chiral Recognition in Gas Chromatography 292.2.1 Chiral Recognition by Hydrogen Bonding 312.2.2 Chiral Recognition Using Chiral Metal Complexes 312.2.3 Chiral Recognition by Host–Guest Interactions 312.3 Preparation of Fused- Silica Capillaries for GC with CSPs 332.4 Application of CSPs in Chiral Gas Chromatography 342.4.1 CSPs with Diamide Selectors 342.4.1.1 Chirasil- Val 342.4.2 CSPs with CD Selectors 352.4.2.1 Heptakis(2,3,6- tri- O- Methyl)- β- Cyclodextrin (Permethyl- β- Cyclodextrin) 382.4.2.2 Heptakis(2,3,6- tri- O- Methyl)- β- Cyclodextrin Immobilized to Hydrido Dimethyl Polysiloxane (Chirasil- β- Dex) 392.4.2.3 Heptakis(2,6- di- O- Methyl- 3- O- Pentyl)- β- Cyclodextrin 432.4.2.4 Hexakis- (2,3,6-tri- O- Pentyl)- α- Cyclodextrin 472.4.2.5 Heptakis(2,3,6- tri- O- Pentyl)- β- Cyclodextrin 482.4.2.6 Hexakis- (3- O- Acetyl- 2,6- di- O- Pentyl)- α- Cyclodextrin 512.4.2.7 Heptakis(3- O- Acetyl- 2,6- di- O- Pentyl)- β- Cyclodextrin 512.4.2.8 Octakis(3- O- Butyryl- 2,6- di- O- Pentyl)- γ- Cyclodextrin 532.4.2.9 Hexakis/Heptakis/Octakis(2,6- di- O- Alkyl- 3- O- Trifluoroacetyl)- α/β/γ- Cyclodextrins 572.4.2.10 Heptakis(2,3- di- O- Acetyl- 6- O-tert- Butyldimethylsilyl)- β- Cyclodextrin (DIAC- 6- TBDMS- β- CD) 582.4.2.11 Heptakis(2,3- di- O- Methyl- 6- O-tert- Butyldimethylsilyl)- β- Cyclodextrin (DIME- 6- TBDMS- β- CD) 582.4.3 Cyclofructans 622.4.4 CSPs with Metal Complexes 652.5 Conclusion 69References 693 Chiral Separation by Supercritical Fluid Chromatography 85Emmanuelle Lipka3.1 Introduction 853.2 Characteristics and Properties of Supercritical Fluids 873.3 Development of a Chiral SFC Method 893.3.1 Chiral Stationary Phases 893.3.2 Mobile Phases 913.3.2.1 Mobile Phase: Type of Co- solvent Used 933.3.2.2 Mobile Phase: Percentage of Co- solvent Used 943.3.2.3 Mobile Phase: Use of Additives 943.4 Operating Parameters 943.4.1 Effect of the Flow Rate 953.4.2 Effect of the Outlet Pressure (Back- pressure) 953.4.2.1 Effect of Pressure When the Mobile Phase is a Gas- Like Fluid 963.4.2.2 Effect of Pressure When the Mobile Phase is a Liquid- Like Fluid 973.4.3 Effect of Temperature 973.4.3.1 Effect of Temperature When the Mobile Phase is a Gas- Like Fluid 983.4.3.2 Effect of Temperature When the Mobile Phase is a Liquid- Like Fluid 983.5 Detection 993.6 Scale- Up to Preparative Separation 993.7 Conclusion 100References 1014 Chiral Separation by Capillary Electrophoresis and Capillary Electrophoresis–Mass Spectrometry: Fundamentals, Recent Developments, and Applications 103Charles Clark, Govert W. Somsen, and Isabelle Kohler4.1 Introduction 1034.2 Principles of Chiral CE 1054.2.1 Electrophoretic Mobility 1054.2.2 CE Separation Efficiency 1064.2.3 Chiral Resolution in CE 1074.2.4 Chiral Micellar Electrokinetic Chromatography and Capillary Electrochromatography 1094.3 Short History of Chiral CE Modes 1114.3.1 Chiral CE 1114.3.2 Chiral MEKC and Chiral CEC 1114.4 State of the Art and Recent Developments 1124.4.1 Common Chiral Selectors 1124.4.2 Ionic Liquids as Chiral Selectors 1174.4.3 Nanoparticles as Chiral Selector Carriers 1174.4.4 Microfluidic Chiral CE 1184.5 Applications of Chiral CE 1194.5.1 Pharmaceutical Analysis 1194.5.2 Food Analysis 1204.5.3 Environmental Analysis 1214.5.4 Bioanalysis 1234.5.5 Forensic Analysis 1264.6 Chiral CE- MS: Strategies and Challenges 1264.6.1 Hyphenation Approaches 1294.6.1.1 Sheath–Liquid and Sheathless CE- MS Interfacing 1294.6.1.2 Partial- Filling Techniques 1304.6.1.3 Counter- Migration Techniques 1314.6.2 Chiral MEKC- MS 1324.6.3 Chiral CEC- MS 1334.7 Conclusions and Perspectives 135References 1355 Chiral Separations at Semi and Preparative Scale 143Larry Miller5.1 Introduction 1435.2 Selection of Operating Conditions 1455.3 Batch HPLC Purification 1465.3.1 Analytical Method Development for Preparative Separations 1465.3.2 Batch HPLC Examples 1485.3.2.1 Batch HPLC Example 1 1485.3.2.2 Batch HPLC Example 2 1495.4 Steady- State Recycle Introduction 1515.4.1 SSR Example 1 1535.5 Simulated Moving Bed Chromatography – Introduction 1545.5.1 SMB Examples for R&D and Separation of Compound 2 1565.5.2 Development of a Manufacturing SMB Process (Compound 1) 1585.5.3 Cost for SMB Processes 1605.6 Introduction to Supercritical Fluid Chromatography 1615.6.1 Analytical Method Development for Scale- up to Preparative SFC 1625.6.2 Preparative SFC Example 1 1635.6.3 Preparative SFC Example 2 1635.7 Options for Increasing Purification Productivity 1655.7.1 Closed- Loop Recycling 1655.7.2 Stacked Injections 1665.7.3 Choosing the Best Synthetic Intermediate for Separation 1675.7.3.1 Choosing Synthetic Step for Separation – HPLC/SMB Example 1685.7.3.2 Choosing Synthetic Step for Separation – SFC Example 1695.7.4 Use of Non- Commercialized CSP 1705.7.5 Immobilized CSP for Preparative Resolution 1735.7.5.1 Processing of Low Solubility Racemate 1735.7.5.2 Preparative Resolution of EMD 53986 1745.8 Choosing a Technique for Preparative Enantioseparation 1765.9 Conclusion 178References 179Part II Chiral Selectors 1876 Polysaccharides 189Weston Umstead, Takafumi Onishi, and Pilar Franco6.1 Introduction 1896.2 The Early Years 1906.3 Polysaccharide Chiral Separation Mechanism 1936.4 Coated Chiral Stationary Phases 1976.5 Immobilized Chiral Stationary Phases 2016.6 Applications of Polysaccharide- Derived CSPs 2086.6.1 Analytical Applications 2106.6.1.1 Pharmaceuticals 2116.6.1.2 Agrochemicals 2186.6.1.3 Food Analysis 2196.6.2 Preparative Applications 2206.7 Summation 224References 2247 Macrocyclic Antibiotics and Cyclofructans 247Saba Aslani, Alain Berthod, and Daniel W. Armstrong7.1 Introduction 2477.2 Macrocyclic Glycopeptides Physicochemical Properties 2487.3 Using the Chiral Macrocyclic Glycopeptides Stationary Phases 2537.3.1 Mobile Phases and Chromatographic Modes 2537.3.2 Chromatographic Enantioseparations 2547.3.2.1 Amino Acids and Peptides 2547.3.2.2 Chiral Compounds 2577.3.2.3 Particle Structure 2577.4 Using and Protecting Macrocyclic Glycopeptide Chiral Columns 2607.4.1 Operating Conditions 2607.4.2 Storage 2617.5 Cyclofructans 2617.5.1 Cyclofructan Structure and Properties 2617.5.2 Chiral Separations with Cyclofructan- Based Stationary Phases 2647.5.3 Cyclofructan Stationary Phases Used in the HILIC Mode 2647.5.4 Cyclofructan Stationary Phases Used in Supercritical Fluid Chromatography 2667.6 Conclusions 267References 2688 Cyclodextrins 273Gerhard K. E. Scriba, Mari- Luiza Konjaria, and Sulaiman Krait8.1 Introduction 2738.2 Structure and Properties 2748.3 Cyclodextrin Complexes 2798.4 Application in Separation Science 2888.4.1 Gas Chromatography 2888.4.1.1 Types of Cyclodextrins 2898.4.1.2 Types of Columns 2898.4.1.3 Separation Mechanisms 2918.4.1.4 Applications 2938.4.2 Thin- Layer Chromatography 2948.4.3 High- Performance Liquid Chromatography 2948.4.3.1 Types of Columns 2958.4.3.2 Types of Cyclodextrins 2978.4.3.3 Separation Mechanisms 2988.4.3.4 Applications 3008.4.4 Supercritical Fluid Chromatography 3008.4.5 Capillary Electromigration Techniques 3018.4.5.1 Types of Cyclodextrins 3018.4.5.2 Separation Mechanisms 3028.4.5.3 Migration Modes and Enantiomer Migration Order Using CDs as Selectors 3048.4.5.4 Applications 3108.4.6 Membrane Technologies 3128.5 Miscellaneous Applications 3148.6 Conclusions and Outlook 315References 3159 Pirkle Type 325Maria Elizabeth Tiritan, Madalena Pinto, and Carla Fernandes9.1 Introduction 3259.2 CSPs Developed by Pirkle’s Group: Chronological Evolution 3279.3 Pirkle- Type CSPs Developed by Other Research Groups 3349.4 Example of Applications in Analytical and Preparative Scales 3409.4.1 Analytical Applications 3419.4.2 Preparative Applications 3499.5 Conclusions and Perspectives 349References 35010 Proteins 363Jun Haginaka10.1 Introduction 36310.2 Preparation of Protein- and Glycoprotein- Based Chiral Stationary Phases 36410.3 Types of Protein- and Glycoprotein- Based Chiral Stationary Phases 36810.3.1 Proteins 36810.3.1.1 Bovine Serum Albumin 36810.3.1.2 Human Serum Albumin 37010.3.1.3 Trypsin and α- Chymotrypsin 37210.3.1.4 Lysozyme and Pepsin 37210.3.1.5 Fatty Acid- Binding Protein 37310.3.1.6 Penicillin G Acylase 37510.3.1.7 Streptavidin 37510.3.1.8 Lipase 37610.3.2 Glycoproteins 37610.3.2.1 Human α 1 - Acid Glycoprotein 37610.3.2.2 Chicken Ovomucoid 37710.3.2.3 Chicken α 1- Acid Glycoprotein 37810.3.2.4 Avidin 38010.3.2.5 Riboflavin- Binding Protein and Ovotransferrin 38010.3.2.6 Cellobiohydrolase 38110.3.2.7 Glucoamylase 38310.3.2.8 Antibody (Immunoglobulin G) 38510.3.2.9 Nicotinic Acetylcholine Receptor and Human Liver Organic Cation Transporter 38710.4 Chiral Recognition Mechanisms on Proteinand Glycoprotein- Based Chiral Stationary Phases 38710.4.1 Human Serum Albumin 38710.4.2 Penicillin G Acylase 38910.4.3 Human α 1- Acid Glycoprotein 39010.4.4 Turkey Ovomucoid 39210.4.5 Chicken α 1- Acid Glycoprotein 39310.4.6 Cellobiohydrolase 39510.4.7 Antibody 39610.4.8 Nicotinic Acetylcholine Receptor and Human Liver Organic Cation Transporter 40010.5 Conclusions 401References 40211 Chiral Stationary Phases Derived from Cinchona Alkaloids 415Michael Lämmerhofer and Wolfgang Lindner11.1 Introduction 41511.2 Cinchona Alkaloid- Derived Chiral Stationary Phases 41611.3 Chiral Recognition 42011.4 Chromatographic Retention Mechanisms 42411.4.1 Multimodal Applicability 42411.4.2 Surface Charge of Cinchonan- Based CSPs 42411.4.3 Retention Mechanisms and Models, and Method Development on Chiral WAX CSPs 42711.4.4 Retention Mechanisms and Method Development on ZWIX CSPs 43011.5 Structural Variants of Cinchona Alkaloid CSPs and Immobilization Chemistries 43611.6 Cinchonan- Based UHPLC Column Technologies 44211.7 Applications 44611.7.1 Pharmaceutical and Biotechnological Applications 44611.7.2 Biomedical Applications 45311.8 Conclusions 460References 460Part III Methods for Stereochemical Elucidation 47312 X- Ray Crystallography for Stereochemical Elucidation 475Ademir F. Morel and Robert A. Burrow12.1 Introduction 47512.2 Absolute Structure and Absolute Configuration 47612.3 Best Practices 48212.4 Structure Validation 48612.5 The Absolute Configuration of (+)- Lanatine A 48612.6 The Absolute Configuration of the Diacetylated Form of Acrenol and the Acetylated Form of Humirianthol 48812.7 The Absolute Configuration of Ester Form of Clemateol 49112.8 Relative Configurations of Waltherione A, Waltherione B, and Vanessine 49212.9 The Absolute Configuration of Condaline A 49312.10 CSD Deposit Numbers 49612.11 Conclusions and Future Directions 498References 49813 NMR for Stereochemical Elucidation 505Xiaolu Li, Xiaoliang Yang, and Han Sun13.1 Conventional NMR Methods for Stereochemical Elucidation 50513.1.1 Determination of the Planar Structure Using 1D 1 H, 13 C NMR (DEPT), 2D HSQC, COSY, TOCSY, HMBC 50613.1.2 Determination of Relative Configuration Using J- Couplings and NOEs/ROEs 50713.1.2.1 Scalar Coupling 50713.1.2.2 NOE/ROE 51013.1.2.3 Examples of Stereochemical Elucidation Using J- Couplings and NOEs/ROEs 51013.2 Determination of the Relative Configuration Using Anisotropic NMR- Based Methods 51613.2.1 Basic Principles of Anisotropic NMR Parameters 51713.2.2 Alignment Media 51813.2.2.1 Preparation of Anisotropic Sample with PMMA Gel 52013.2.2.2 Preparation of Anisotropic Sample with AAKLVFF 52113.2.3 Acquisition of the Anisotropic NMR Data 52213.2.4 Computational Approaches for Analyzing Anisotropic NMR Data 52513.2.5 Successful Examples of Determination of Relative Configuration of Challenging Molecules Using Anisotropic NMR 52813.3 Determination of the Relative Configuration Using DP 4 Probability and CASE- 3D 52913.4 Determination of the Absolute Configuration Using a Combination of NMR Spectroscopy and Chiroptical Spectroscopy 53313.5 Determination of the Absolute Configuration Using NMR Alone 53413.5.1 Mosher Ester Analysis 53513.5.2 Other Chiral Derivatizing Agents 53613.6 Future Perspective 536References 53714 Absolute Configuration from Chiroptical Spectroscopy 551Fernando Martins dos Santos Junior and João Marcos Batista Junior14.1 Introduction 55114.2 Chiroptical Methods 55414.2.1 Optical Rotation and Optical Rotatory Dispersion 55414.2.1.1 Instrumentation 55614.2.1.2 Measurements 55714.2.2 Electronic Circular Dichroism 55814.2.2.1 Instrumentation 56014.2.2.2 Measurements 56114.2.3 Vibrational Circular Dichroism and Raman Optical Activity 56114.2.3.1 Instrumentation 56314.2.3.2 Measurements 56514.2.4 Simulation of Chiroptical Properties 56714.2.4.1 Common Theoretical Steps 56814.2.4.2 OR and ORD Simulations 57014.2.4.3 ECD Simulations 57214.2.4.4 VCD and ROA Simulations 57314.2.5 Examples of Application 57514.2.5.1 OR 57514.2.5.2 ORD 57714.2.5.3 ECD 57814.2.5.4 VCD 57914.2.5.5 ROA 58114.2.5.6 Association of Different Chiroptical Methods 58214.3 Concluding Remarks 585References 586Index 593