Catalyst-Free "On-Water" Regio- and Stereospecific Ring-Opening of Spiroaziridine Oxindole: Enantiopure Synthesis of Unsymmetrical 3,3'-Bisindoles.
Hajra, Saumen; Singha Roy, Somnath; Aziz, Sk Mohammad; Das, Dhiraj; Organic letters 19 (2017) 4082–4085; doi:10.1021/acs.orglett.7b01833

data_1556074
_publ_section_title
;
 Catalyst-Free &quot;On-Water&quot; Regio- and Stereospecific Ring-Opening
 of Spiroaziridine Oxindole: Enantiopure Synthesis of Unsymmetrical
 3,3'-Bisindoles.
;
_journal_issue                   15
_journal_name_full               'Organic letters'
_journal_page_first              4082
_journal_page_last               4085
_journal_paper_doi               10.1021/acs.orglett.7b01833
_journal_volume                  19
_journal_year                    2017
_chemical_absolute_configuration S
_chemical_formula_moiety         'C22 H25 N3 O3 S, 0.5(H2 O)'
_chemical_formula_sum            'C22 H26 N3 O3.5 S'
_chemical_formula_weight         420.53
_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
_audit_creation_method           SHELXL-2016/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   12.3073(15)
_cell_length_b                   18.643(2)
_cell_length_c                   20.256(2)
_cell_measurement_reflns_used    53708
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24.800
_cell_measurement_theta_min      1.484
_cell_volume                     4647.6(9)
_computing_structure_refinement  'SHELXL-2016/6 (Sheldrick, 2016)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Venture D8'
_diffrn_measurement_method       '\ w scan'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1172
_diffrn_reflns_av_unetI/netI     0.0904
_diffrn_reflns_Laue_measured_fraction_full 0.994
_diffrn_reflns_Laue_measured_fraction_max 0.994
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            53708
_diffrn_reflns_point_group_measured_fraction_full 0.992
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        24.800
_diffrn_reflns_theta_max         24.800
_diffrn_reflns_theta_min         1.484
_exptl_absorpt_coefficient_mu    0.168
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.199
_exptl_crystal_description       block
_exptl_crystal_F_000             1776
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.487
_refine_diff_density_min         -0.169
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details
;
 Flack x determined using 1223 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.12(8)
_refine_ls_extinction_coef       0.0009(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2016/6 (Sheldrick 2016)'
_refine_ls_goodness_of_fit_ref   0.978
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     541
_refine_ls_number_reflns         7954
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.978
_refine_ls_R_factor_all          0.1335
_refine_ls_R_factor_gt           0.0704
_refine_ls_shift/su_max          0.046
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0997P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1726
_refine_ls_wR_factor_ref         0.2010
_reflns_Friedel_coverage         0.794
_reflns_Friedel_fraction_full    0.990
_reflns_Friedel_fraction_max     0.990
_reflns_number_gt                4095
_reflns_number_total             7954
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol7b01833_si_002.cif
_cod_data_source_block           shelx
_cod_depositor_comments
;

2025-06-17
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_formula_sum            'C16 H18.18 N2.18 O2.55 S0.73'
_cod_original_formula_weight         305.10
_cod_original_formula_moiety         'C16 H18.18 N2.18 O2.55 S0.73'
_cod_original_formula_units_Z            11
_cod_original_cell_volume        4647.7(10)
_cod_database_code               1556074
_shelx_shelxl_version_number     2016/6
_shelx_estimated_absorpt_t_min   0.967
_shelx_estimated_absorpt_t_max   0.983
_shelx_res_checksum              44770
_shelx_hkl_checksum              1912