Molecular iodine catalyzed C3-quaternization via oxidative dearomatization of indoles: direct access to 3,3-di(indolyl)indolin-2-ones
Singh, Neetika; Kokatla, Hari Prasad; Naddi, Nagaraju; Inapanuri, Madhu; RSC Advances 16 (2026) 7967–7973; doi:10.1039/D6RA00218H

data_7251610
_publ_section_title
;
 Molecular iodine catalyzed C3-quaternization via oxidative
 dearomatization of indoles: direct access to
 3,3-di(indolyl)indolin-2-ones
;
_journal_issue                   9
_journal_name_full               'RSC Advances'
_journal_page_first              7967
_journal_page_last               7973
_journal_paper_doi               10.1039/D6RA00218H
_journal_volume                  16
_journal_year                    2026
_chemical_formula_moiety         'C27 H23 N3 O'
_chemical_formula_sum            'C27 H23 N3 O'
_chemical_formula_weight         405.48
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2023-09-28
_audit_creation_method
;
Olex2 1.3-ac4
(compiled 2018.12.18 svn.r3554 for Rigaku Oxford Diffraction, GUI svn.r1)
;
_audit_update_record
;
2025-09-23 deposited with the CCDC.	2026-02-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.530(6)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.2233(18)
_cell_length_b                   21.237(3)
_cell_length_c                   9.1008(12)
_cell_measurement_reflns_used    9960
_cell_measurement_temperature    297(2)
_cell_measurement_theta_max      27.23
_cell_measurement_theta_min      2.34
_cell_volume                     2125.4(5)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_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    'olex2.solve (Bourhis et al., 2015)'
_diffrn_ambient_temperature      297.0
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.993
_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  0.0595
_diffrn_reflns_av_unetI/netI     0.0402
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            33877
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.623
_diffrn_reflns_theta_min         1.852
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.078
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.3523
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1633 before and 0.0872 after correction.
The Ratio of minimum to maximum transmission is 0.4725.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            'metallic orangish orange'
_exptl_crystal_colour_lustre     metallic
_exptl_crystal_colour_modifier   orangish
_exptl_crystal_colour_primary    orange
_exptl_crystal_density_diffrn    1.267
_exptl_crystal_description       block
_exptl_crystal_F_000             856
_exptl_crystal_size_max          0.201
_exptl_crystal_size_mid          0.121
_exptl_crystal_size_min          0.111
_refine_diff_density_max         0.267
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.057
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     283
_refine_ls_number_reflns         4913
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.062
_refine_ls_R_factor_all          0.0714
_refine_ls_R_factor_gt           0.0553
_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^)+(0.0765P)^2^+0.5101P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1531
_refine_ls_wR_factor_ref         0.1624
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3696
_reflns_number_total             4913
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6ra00218h2.cif
_cod_data_source_block           exter108_0m_a
_cod_database_code               7251610
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.991
_shelx_estimated_absorpt_t_min   0.984
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C1(H1), C13(H13), C4(H4), C18(H18), C5(H5), C12(H12), C7(H7), C10(H10),
 C23(H23), C11(H11), C6(H6), C20(H20), C22(H22), C21(H21)
2.b Idealised Me refined as rotating group:
 C26(H26A,H26B,H26C), C27(H27A,H27B,H27C), C25(H25A,H25B,H25C)
;
_shelx_res_checksum              51040
_olex2_submission_special_instructions 'No special instructions were received'