K<sup>+</sup>/Cu<sup>2+</sup> Co-chelated diastereoselective Friedel-Crafts reaction with chiral <i>N</i>-sulfinyl ketimines for the facile synthesis of chiral bisindoles and their cytotoxicity.
Yan, Si; Xu, Mengwei; Liu, Yan; Du, Ziwei; Zhang, Guangshuai; Liu, Zishu; Xiao, Jin; Guo, Xiaoqian; Liao, Gang; Min, Qing; Xie, Baocheng; Qin, Shuanglin; RSC advances 16 (2026) 7337–7343; doi:10.1039/d5ra09219a

data_7251727
_publ_section_title
;
 K<sup>+</sup>/Cu<sup>2+</sup> Co-chelated diastereoselective
 Friedel-Crafts reaction with chiral <i>N</i>-sulfinyl ketimines for the
 facile synthesis of chiral bisindoles and their cytotoxicity.
;
_journal_issue                   8
_journal_name_full               'RSC advances'
_journal_page_first              7337
_journal_page_last               7343
_journal_paper_doi               10.1039/d5ra09219a
_journal_volume                  16
_journal_year                    2026
_chemical_absolute_configuration unk
_chemical_formula_moiety         '0.5(C21 H23 N3 O2 S), 0.458[CH3COOCH2CH3]'
_chemical_formula_sum            'C21 H23 N3 O2 S'
_chemical_formula_weight         381.48
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2024-06-21
_audit_creation_method
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_audit_update_record
;
2025-02-13 deposited with the CCDC.	2026-01-29 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.4468(16)
_cell_length_b                   12.9783(11)
_cell_length_c                   19.993(3)
_cell_measurement_reflns_used    8368
_cell_measurement_temperature    301.00
_cell_measurement_theta_max      72.10
_cell_measurement_theta_min      4.06
_cell_volume                     2710.7(6)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'olex2.solve 1.5 (Bourhis et al., 2015)'
_diffrn_ambient_temperature      301.00
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0592
_diffrn_reflns_av_unetI/netI     0.0443
_diffrn_reflns_Laue_measured_fraction_full 0.991
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            26816
_diffrn_reflns_point_group_measured_fraction_full 0.990
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         72.184
_diffrn_reflns_theta_min         4.061
_diffrn_source_current           1.1
_diffrn_source_power             0.05500000000000001
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.181
_exptl_absorpt_correction_T_max  0.7536
_exptl_absorpt_correction_T_min  0.6182
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1092 before and 0.0668 after correction.
The Ratio of minimum to maximum transmission is 0.8203.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    0.935
_exptl_crystal_description       block
_exptl_crystal_F_000             808
_exptl_crystal_size_max          0.54
_exptl_crystal_size_mid          0.48
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.366
_refine_diff_density_min         -0.328
_refine_diff_density_rms         0.071
_refine_ls_abs_structure_details
;
 Flack x determined using 1867 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.029(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.076
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     248
_refine_ls_number_reflns         5289
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.076
_refine_ls_R_factor_all          0.0729
_refine_ls_R_factor_gt           0.0597
_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^)+(0.1558P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1739
_refine_ls_wR_factor_ref         0.1976
_reflns_Friedel_coverage         0.768
_reflns_Friedel_fraction_full    0.987
_reflns_Friedel_fraction_max     0.988
_reflns_number_gt                4668
_reflns_number_total             5289
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra09219a2.cif
_cod_data_source_block           cu_1s_0m_a
_cod_original_cell_volume        2710.7(7)
_cod_database_code               7251727
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.757
_shelx_estimated_absorpt_t_min   0.568
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Aromatic/amide H refined with riding coordinates:
 N2(H2), N3(H3), C8(H8), C14(H14), C1(H1), C16(H16), C15(H15), C13(H13),
 C4(H4), C3(H3A), C2(H2A)
2.b Idealised Me refined as rotating group:
 C19(H19A,H19B,H19C), C20(H20A,H20B,H20C), C11(H11A,H11B,H11C), C21(H21A,H21B,
 H21C)
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_smtbx_masks_special_details
;
A solvent mask was calculated and 176 electrons were 
found in a volume of 1036\%A^3^ in 1 void per unit cell. 
This is consistent with the presence of 
0.458[CH3COOCH2CH3] per formula unit 
which account for 176 electrons 
per unit cell.
;
_smtbx_masks_void_probe_radius   1.2
_smtbx_masks_void_truncation_radius 1.2
_shelx_res_checksum              25324
_shelx_fab_checksum              24924
_olex2_submission_special_instructions 'No special instructions were received'