N-Heterocyclic carbenes as chiral Brønsted base catalysts: a highly diastereo- and enantioselective 1,6-addition reaction.
Santra, Surojit; Porey, Arka; Jana, Barun; Guin, Joyram; Chemical science 9 (2018) 6446–6450; doi:10.1039/c8sc02138d

data_1549641
_publ_section_title
;
 N-Heterocyclic carbenes as chiral Br\/onsted base catalysts: a highly
 diastereo- and enantioselective 1,6-addition reaction.
;
_journal_issue                   30
_journal_name_full               'Chemical science'
_journal_page_first              6446
_journal_page_last               6450
_journal_paper_doi               10.1039/c8sc02138d
_journal_volume                  9
_journal_year                    2018
_chemical_absolute_configuration ad
_chemical_formula_sum            'C35 H40 N2 O4'
_chemical_formula_weight         552.69
_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'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/6
_audit_update_record
;
2018-03-21 deposited with the CCDC.
2018-07-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 111.316(6)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.151(3)
_cell_length_b                   14.717(4)
_cell_length_c                   16.184(3)
_cell_measurement_reflns_used    9868
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.20
_cell_measurement_theta_min      2.39
_cell_volume                     3139.9(12)
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.963
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0680
_diffrn_reflns_av_unetI/netI     0.0952
_diffrn_reflns_Laue_measured_fraction_full 0.963
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            18150
_diffrn_reflns_point_group_measured_fraction_full 0.815
_diffrn_reflns_point_group_measured_fraction_max 0.838
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         24.999
_diffrn_reflns_theta_min         2.702
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.169
_exptl_crystal_description       block
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.030
_exptl_crystal_size_mid          0.020
_exptl_crystal_size_min          0.020
_refine_diff_density_max         0.583
_refine_diff_density_min         -0.302
_refine_diff_density_rms         0.074
_refine_ls_abs_structure_details
;
 Flack x determined using 2944 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.3(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.951
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     759
_refine_ls_number_reflns         9257
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.951
_refine_ls_R_factor_all          0.0722
_refine_ls_R_factor_gt           0.0679
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1425P)^2^+0.3068P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1771
_refine_ls_wR_factor_ref         0.1835
_reflns_Friedel_coverage         0.624
_reflns_Friedel_fraction_full    0.654
_reflns_Friedel_fraction_max     0.673
_reflns_number_gt                8486
_reflns_number_total             9257
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8sc02138d2.cif
_cod_data_source_block           mo_OCJG310118_0m_a
_cod_depositor_comments
;

2019-03-02
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel

 Adding full bibliography for 1549640--1549642.cif.
;
_cod_original_formula_sum        'C70 H80 N4 O8'
_cod_original_formula_units_Z    2
_cod_original_formula_weight     1105.38
_cod_database_code               1549641
_shelx_estimated_absorpt_t_min   0.998
_shelx_estimated_absorpt_t_max   0.998
_shelxl_version_number           2014/6
_shelx_res_checksum              57973