Efficient synthesis of pyrrolo[1,2-<i>a</i>]indol-3-ones through a radical-initiated cascade cyclization reaction.
Zhang, Han; Lin, Yuze; Yang, Gang; Yang, Xifa; Cui, Xiuling; Organic & biomolecular chemistry 23 (2025) 4966–4970; doi:10.1039/d5ob00474h

data_7160510
_publ_section_title
;
 Efficient synthesis of pyrrolo[1,2-<i>a</i>]indol-3-ones through a
 radical-initiated cascade cyclization reaction.
;
_journal_issue                   20
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              4966
_journal_page_last               4970
_journal_paper_doi               10.1039/d5ob00474h
_journal_volume                  23
_journal_year                    2025
_chemical_formula_moiety         'C23 H21 N3 O'
_chemical_formula_sum            'C23 H21 N3 O'
_chemical_formula_weight         355.43
_chemical_melting_point          401.15
_chemical_name_systematic
3-(1-imino-2-methyl-3-oxo-9-phenyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-2-yl)-2,2-dimethylpropanenitrile
_chemical_properties_physical    Heat-sensitive,Oxygen-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2024-01-08
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_audit_update_record
;
2025-01-01 deposited with the CCDC.	2025-04-22 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 100.182(11)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   22.050(2)
_cell_length_b                   8.2245(13)
_cell_length_c                   21.735(3)
_cell_measurement_reflns_used    2395
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      23.2280
_cell_measurement_theta_min      3.1630
_cell_volume                     3879.6(9)
_computing_cell_refinement       'CrysAlisPro 1.171.42.99a (Rigaku OD, 2023)'
_computing_data_collection       'CrysAlisPro 1.171.42.99a (Rigaku OD, 2023)'
_computing_data_reduction        'CrysAlisPro 1.171.42.99a (Rigaku OD, 2023)'
_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    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 8.0606
_diffrn_detector_type            Eos
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w    -40.00  42.80   0.90    1.50    --   17.12 -30.00-165.00   92
  2  \w    -40.00   8.60   0.90    1.50    --  -17.59  30.00  -4.00   54
  3  \w     38.00  75.80   0.90    1.50    --   17.12-178.00-150.00   42
  4  \w    -38.00  -2.00   0.90    1.50    --  -17.59 -77.00  90.00   40
  5  \w    -32.00   6.70   0.90    1.50    --  -17.59 -77.00-180.00   43
  6  \w    -22.00  10.40   0.90    1.50    --  -17.59 -77.00   0.00   36
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0005486000
_diffrn_orient_matrix_UB_12      -0.0484856000
_diffrn_orient_matrix_UB_13      0.0270757000
_diffrn_orient_matrix_UB_21      -0.0126232000
_diffrn_orient_matrix_UB_22      0.0653077000
_diffrn_orient_matrix_UB_23      0.0149365000
_diffrn_orient_matrix_UB_31      -0.0301381000
_diffrn_orient_matrix_UB_32      -0.0282493000
_diffrn_orient_matrix_UB_33      -0.0121304000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0345
_diffrn_reflns_av_unetI/netI     0.0566
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            9870
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.366
_diffrn_reflns_theta_min         2.758
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.06672
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.42.99a (Rigaku Oxford Diffraction, 2023)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.217
_exptl_crystal_description       block
_exptl_crystal_F_000             1504
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: Dichloromethane/n-Hexane'
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.246
_refine_diff_density_min         -0.163
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.092
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         3961
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.092
_refine_ls_R_factor_all          0.1348
_refine_ls_R_factor_gt           0.0955
_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^)+(0.0715P)^2^+10.2807P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2265
_refine_ls_wR_factor_ref         0.2472
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2636
_reflns_number_total             3961
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob00474h3.cif
_cod_data_source_block           exp_13843_auto
_cod_depositor_comments          'Adding full bibliography for 7160510.cif.'
_cod_original_cell_volume        3879.4(9)
_cod_database_code               7160510
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_max   0.992
_shelx_estimated_absorpt_t_min   0.987
_reflns_odcompleteness_completeness 99.72
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 N2-H2
 0.87 with sigma of 0.02
3. Uiso/Uaniso restraints and constraints
Uanis(N3) = Uanis(N3A)
Uanis(C23) = Uanis(C23A)
Uanis(C22) = Uanis(C22A)
4. Others
 Sof(N3A)=Sof(C22A)=Sof(H22D)=Sof(H22E)=Sof(H22F)=Sof(C23A)=1-FVAR(1)
 Sof(N3)=Sof(C22)=Sof(H22A)=Sof(H22B)=Sof(H22C)=Sof(C23)=FVAR(1)
5.a Secondary CH2 refined with riding coordinates:
 C19(H19A,H19B)
5.b Aromatic/amide H refined with riding coordinates:
 C8(H8), C9(H9), C10(H10), C11(H11), C13(H13), C14(H14), C15(H15), C16(H16),
 C17(H17)
5.c Idealised Me refined as rotating group:
 C18(H18A,H18B,H18C), C21(H21A,H21B,H21C), C22(H22A,H22B,H22C), C22A(H22D,H22E,
 H22F)
;
_shelx_res_checksum              8244
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 11.920
_oxdiff_exptl_absorpt_empirical_full_min 0.715