Synthesis and Conformational Properties of 3,4-Difluoro-l-prolines.
Hofman, Gert-Jan; Ottoy, Emile; Light, Mark E.; Kieffer, Bruno; Martins, Jose C.; Kuprov, Ilya; Sinnaeve, Davy; Linclau, Bruno; The Journal of organic chemistry 84 (2019) 3100–3120; doi:10.1021/acs.joc.8b02920

data_4033904
_publ_section_title
;
 Synthesis and Conformational Properties of 3,4-Difluoro-l-prolines.
;
_journal_issue                   6
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              3100
_journal_page_last               3120
_journal_paper_doi               10.1021/acs.joc.8b02920
_journal_volume                  84
_journal_year                    2019
_chemical_formula_moiety         'C14 H15 N O4'
_chemical_formula_sum            'C14 H15 N O4'
_chemical_formula_weight         261.27
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2016-05-18
_audit_creation_method
;
Olex2 1.2-alpha
(compiled 2016.02.24 svn.r3266 for OlexSys, GUI svn.r5155)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   7.4200(2)
_cell_length_b                   13.6927(3)
_cell_length_c                   24.5834(5)
_cell_measurement_reflns_used    26524
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      71.836
_cell_measurement_theta_min      3.596
_cell_volume                     2497.67(10)
_computing_cell_refinement
;
Rigaku (2004). RAPID-AUTO Ver. 3.1.1 Rigaku Corporation, Tokyo, Japan 
;
_computing_data_collection
;
Rigaku (2004). RAPID-AUTO Ver. 3.1.1 Rigaku Corporation, Tokyo, Japan 
;
_computing_data_reduction
;
Rigaku (2004). RAPID-AUTO Ver. 3.1.1 Rigaku Corporation, Tokyo, Japan 
;
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'Image plate'
_diffrn_detector_area_resol_mean 10
_diffrn_detector_type            'Rigaku Curved Fujifilm'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device       'three-circle quarter \c goniometer'
_diffrn_measurement_device_type  'Rigaku R-AXIS Spider'
_diffrn_measurement_method       'profile data from oscillation \w-scans'
_diffrn_measurement_specimen_support 'MiTeGen MicroMesh'
_diffrn_radiation_collimation    0.5
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.0317
_diffrn_reflns_av_unetI/netI     0.0159
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            26524
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        67.687
_diffrn_reflns_theta_max         71.836
_diffrn_reflns_theta_min         3.596
_diffrn_source                   'sealed x-ray tube'
_diffrn_source_current           55.0
_diffrn_source_power             2.475
_diffrn_source_target            Cu
_diffrn_source_voltage           45.0
_exptl_absorpt_coefficient_mu    0.851
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.6695
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Jacobson, R. (1998). REQAB. Private communication to the 
Rigaku Corporation, Tokyo, Japan 
;
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.390
_exptl_crystal_description       slab
_exptl_crystal_F_000             1104
_exptl_crystal_recrystallization_method
'The material was recrystallised from DCM by slow evaporation'
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.212
_refine_diff_density_min         -0.207
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.095
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     173
_refine_ls_number_reflns         2432
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.095
_refine_ls_R_factor_all          0.0382
_refine_ls_R_factor_gt           0.0373
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0402P)^2^+1.2440P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0914
_refine_ls_wR_factor_ref         0.0920
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2375
_reflns_number_total             2432
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo8b02920_si_003.cif
_cod_data_source_block           2016sot0035_s1_100k
_cod_database_code               4033904
_diffrn_measurement_device_type2 'Rigaku R-AXIS SPIDER IP'
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C4(H4), C5(H5), C6(H6)
2.b Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C8(H8A,H8B)
2.c Aromatic/amide H refined with riding coordinates:
 C10(H10), C11(H11), C12(H12), C13(H13), C14(H14)
2.d Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C)
;
_shelx_res_checksum              30322
_shelx_hkl_checksum              22614
_shelx_shelxl_version_number     2014/7
_olex2_date_sample_submission    2016-05-04
_olex2_diffrn_ambient_temperature_device 'Oxford Cryosystems'
_olex2_exptl_crystal_mounting_method
'The crystal was mounted on a MITIGEN holder silicon oil'
_olex2_submission_original_sample_id 'GJH-49 Sputz '
_olex2_submission_special_instructions 'No special instructions were received'