Catalytic Enantioselective Synthesis of Difluorinated Alkyl Bromides.
Levin, Mark D.; Ovian, John M.; Read, Jacquelyne A.; Sigman, Matthew S.; Jacobsen, Eric N.; Journal of the American Chemical Society 142 (2020) 14831–14837; doi:10.1021/jacs.0c07043

data_4135206
_publ_section_title
;
 Catalytic Enantioselective Synthesis of Difluorinated Alkyl Bromides.
;
_journal_issue                   35
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              14831
_journal_page_last               14837
_journal_paper_doi               10.1021/jacs.0c07043
_journal_volume                  142
_journal_year                    2020
_chemical_absolute_configuration ad
_chemical_formula_sum            'C18 H15 Br F2 N4 O2'
_chemical_formula_weight         437.25
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 112.3222(18)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   12.6771(15)
_cell_length_b                   5.6603(7)
_cell_length_c                   13.2825(15)
_cell_measurement_reflns_used    3964
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.0
_cell_measurement_theta_min      3.12
_cell_volume                     881.68(18)
_computing_cell_refinement       'SAINT 8.37A (Bruker-AXS, 2015)'
_computing_data_reduction        'SAINT 8.37A (Bruker-AXS, 2015)'
_computing_molecular_graphics    'Bruker SHELXTL (Sheldrick, 2015)'
_computing_publication_material  'Bruker SHELXTL (Sheldrick, 2015)'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT-2014 (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type
;
Bruker D8 goniometer with CCD area detector  
;
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'I\mS microfocus tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0299
_diffrn_reflns_av_unetI/netI     0.0652
_diffrn_reflns_Laue_measured_fraction_full 0.995
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            5582
_diffrn_reflns_point_group_measured_fraction_full 0.956
_diffrn_reflns_point_group_measured_fraction_max 0.935
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.108
_diffrn_reflns_theta_min         1.657
_exptl_absorpt_coefficient_mu    2.373
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.5647
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.647
_exptl_crystal_description       block
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.100
_exptl_crystal_size_mid          0.040
_exptl_crystal_size_min          0.020
_refine_diff_density_max         1.127
_refine_diff_density_min         -0.381
_refine_diff_density_rms         0.100
_refine_ls_abs_structure_details
;
 Flack x determined using 1028 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.004(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         3654
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0683
_refine_ls_R_factor_gt           0.0505
_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^)+(0.0656P)^2^+0.0622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1106
_refine_ls_wR_factor_ref         0.1193
_reflns_Friedel_coverage         0.708
_reflns_Friedel_fraction_full    0.907
_reflns_Friedel_fraction_max     0.864
_reflns_number_gt                2999
_reflns_number_total             3654
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja0c07043_si_003.cif
_cod_data_source_block           MLII-99-2
_cod_depositor_comments          'Adding full bibliography for 4135206.cif.'
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4135206
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.797
_shelx_estimated_absorpt_t_max   0.954
_shelx_res_checksum              34544
_shelx_hkl_checksum              81683