N-Heterocyclic Carbene-Catalyzed Umpolung of Imines for the Enantioselective Synthesis of Dihydroquinoxalines
Das, Tamal Kanti; Ghosh, Avik; Balanna, Kuruva; Behera, Pradipta; Gonnade, Rajesh G.; Marelli, Udaya Kiran; Das, Abhijit Kumar; Biju, Akkattu T.; ACS Catalysis 9 (2019) 4065–; doi:10.1021/acscatal.9b00737

data_4514715
_publ_section_title
;
 N-Heterocyclic Carbene-Catalyzed Umpolung of Imines for the
 Enantioselective Synthesis of Dihydroquinoxalines
;
_journal_issue                   5
_journal_name_full               'ACS Catalysis'
_journal_page_first              4065
_journal_paper_doi               10.1021/acscatal.9b00737
_journal_volume                  9
_journal_year                    2019
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C20 H15 Br N2 O2, CH3COCH3'
_chemical_formula_sum            'C23 H21 Br N2 O3'
_chemical_formula_weight         453.33
_space_group_crystal_system      trigonal
_space_group_IT_number           145
_space_group_name_Hall           'P 32'
_space_group_name_H-M_alt        'P 32'
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            3
_cell_length_a                   9.5332(3)
_cell_length_b                   9.5332(3)
_cell_length_c                   19.5349(8)
_cell_measurement_reflns_used    9922
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      35.93
_cell_measurement_theta_min      2.68
_cell_volume                     1537.51(9)
_computing_cell_refinement       'SAINT (Bruker, 2016)'
_computing_data_collection       'APEX3 (Bruker, 2016)'
_computing_data_reduction        'SAINT (Bruker, 2016)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'Photon II CPAD Area Detector'
_diffrn_detector_area_resol_mean 7.39
_diffrn_measured_fraction_theta_full 0.970
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Bruker D8 VENTURE Kappa Duo PHOTON II CPAD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'multilayer mirrors'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0259
_diffrn_reflns_av_unetI/netI     0.0405
_diffrn_reflns_Laue_measured_fraction_full 0.970
_diffrn_reflns_Laue_measured_fraction_max 0.977
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            21345
_diffrn_reflns_point_group_measured_fraction_full 0.943
_diffrn_reflns_point_group_measured_fraction_max 0.955
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.990
_diffrn_reflns_theta_min         2.678
_diffrn_source                   'micro-focus sealed tube'
_diffrn_source_type              'Incoatech I\mS HB'
_exptl_absorpt_coefficient_mu    2.032
_exptl_absorpt_correction_T_max  0.888
_exptl_absorpt_correction_T_min  0.675
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (BRUKER, 2016)'
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.469
_exptl_crystal_description       PLATE
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.210
_exptl_crystal_size_mid          0.140
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.285
_refine_diff_density_min         -0.303
_refine_diff_density_rms         0.037
_refine_ls_abs_structure_details
;
 Flack x determined using 2150 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.022(3)
_refine_ls_extinction_coef       0.012(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     275
_refine_ls_number_reflns         4748
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0205
_refine_ls_R_factor_gt           0.0193
_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^)+0.1415P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0478
_refine_ls_wR_factor_ref         0.0480
_reflns_Friedel_coverage         0.954
_reflns_Friedel_fraction_full    0.916
_reflns_Friedel_fraction_max     0.932
_reflns_number_gt                4587
_reflns_number_total             4748
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            cs9b00737_si_002.cif
_cod_data_source_block           TKDTF47_F2
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'MULTI-SCAN' changed to
'multi-scan' according to
/home/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4973 2017-02-22 13:04:09Z antanas 
;
_cod_original_cell_volume        1537.51(12)
_cod_database_code               4514715
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.675
_shelx_estimated_absorpt_t_max   0.888
_shelx_res_checksum              4257
_shelx_hkl_checksum              89939