Synthesis of planar chiral biferrocenes by iridium-catalyzed [2+2+2] cycloadition of a biferrocene-linked diyne with nitriles: asymmetric desymmetrization and kinetic resolution
Sawano, Takahiro; Murata, Kayo; Suzaki, Tomoaki; Urasawa, Kazuki; Kobayashi, Manami; Aso, Ryota; Ozasa, Kazuki; Ishikawa, Eri; Takeuchi, Ryo; Chemical Communications  (2026) –; doi:10.1039/D6CC00435K

data_7135699
_publ_section_title
;
 Synthesis of planar chiral biferrocenes by iridium-catalyzed [2+2+2]
 cycloaddition of biferrocene-linked diynes with nitriles: asymmetric
 desymmetrization and kinetic resolution.
;
_journal_issue                   33
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              8451
_journal_page_last               8455
_journal_paper_doi               10.1039/d6cc00435k
_journal_volume                  62
_journal_year                    2026
_chemical_formula_moiety         'C24 H18 Fe2'
_chemical_formula_sum            'C24 H18 Fe2'
_chemical_formula_weight         418.08
_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     dual
_audit_creation_date             2026-03-08
_audit_creation_method
;
Olex2 1.5-ac7-018
(compiled 2025.08.06 svn.rb7424aed for Rigaku Oxford Diffraction, GUI svn.r7314)
;
_audit_update_record
;
2026-03-23 deposited with the CCDC.	2026-04-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 106.310(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   18.1049(5)
_cell_length_b                   7.4356(2)
_cell_length_c                   13.5342(4)
_cell_measurement_reflns_used    6078
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      78.8490
_cell_measurement_theta_min      5.0600
_cell_volume                     1748.66(9)
_computing_cell_refinement       'CrysAlisPro 1.171.44.128a (Rigaku OD, 2025)'
_computing_data_collection
'CrysAlisPro system (CCD 44.128a 64-bit (release 04-11-2025))'
_computing_data_reduction        'CrysAlisPro 1.171.44.128a (Rigaku OD, 2025)'
_computing_molecular_graphics    'Olex2 1.5-ac7-018 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-ac7-018 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.00(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.903
_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   -110.00 -74.00   0.50    0.56    --  -48.61-125.00 -60.00   72
  2  \w   -129.00 -84.00   0.50    2.22    --  -91.75 -34.00   7.00   90
  3  \w   -121.00 -38.00   0.50    0.56    --  -48.61 -34.00   7.00  166
  4  \w    -62.00 -32.00   0.50    2.22    --  -91.75  57.00  90.00   60
  5  \w    -53.00 -20.00   0.50    2.22    --  -91.75  77.00 120.00   66
  6  \w    -65.00 -31.00   0.50    2.22    --  -91.75  57.00 120.00   68
  7  \w   -113.00 -58.00   0.50    2.22    --  -91.75  77.00 120.00  110
  8  \w    -64.00 -31.00   0.50    2.22    --  -91.75  57.00 -30.00   66
  9  \w    -66.00 -27.00   0.50    2.22    --  -91.75  57.00 -60.00   78
 10  \w    -66.00 -40.00   0.50    2.22    --  -91.75  57.00 -90.00   52
 11  \w    -64.00 -29.00   0.50    2.22    --  -91.75  57.00-120.00   70
 12  \w    -64.00 -28.00   0.50    2.22    --  -91.75  57.00-180.00   72
 13  \w    -12.00  27.00   0.50    0.56    --  -48.61  19.00 -60.00   78
 14  \w    -33.00  13.00   0.50    0.56    --  -48.61  34.00 165.00   92
 15  \w    -60.00 -34.00   0.50    2.22    --  -91.75  57.00   0.00   52
 16  \w    -47.00 -21.00   0.50    2.22    --  -91.75 125.00-150.00   52
 17  \w    -44.00 -19.00   0.50    2.22    --  -91.75 125.00-180.00   50
 18  \w    -83.00 -53.00   0.50    2.22    --  -91.75 125.00-150.00   60
 19  \w     56.00  83.00   0.50    2.22    --  113.25 -99.00-180.00   54
 20  \w     -1.00  34.00   0.50    0.56    --   48.61 -34.00   7.00   70
 21  \w     64.00 102.00   0.50    2.22    --  113.25 -99.00 120.00   76
 22  \w     42.00 119.00   0.50    0.56    --   48.61  34.00 165.00  154
 23  \w    100.00 169.00   0.50    2.22    --  113.25  34.00 165.00  138
 24  \w    107.00 176.00   0.50    2.22    --  113.25 125.00 -30.00  138
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0866812000
_diffrn_orient_matrix_UB_12      0.0046087000
_diffrn_orient_matrix_UB_13      -0.0562982000
_diffrn_orient_matrix_UB_21      0.0174339000
_diffrn_orient_matrix_UB_22      0.0895439000
_diffrn_orient_matrix_UB_23      -0.0936513000
_diffrn_orient_matrix_UB_31      0.0062458000
_diffrn_orient_matrix_UB_32      -0.1866441000
_diffrn_orient_matrix_UB_33      -0.0463878000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0323
_diffrn_reflns_av_unetI/netI     0.0307
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.903
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       4
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            12122
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.903
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         79.139
_diffrn_reflns_theta_min         5.091
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    13.306
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.620
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.128a (Rigaku Oxford Diffraction, 2025)
Numerical absorption correction based on gaussian integration over
a multifaceted crystal model
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light orange'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    orange
_exptl_crystal_density_diffrn    1.588
_exptl_crystal_description       block
_exptl_crystal_F_000             856
_exptl_crystal_preparation       recrystalization
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.07
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.923
_refine_diff_density_min         -0.494
_refine_diff_density_rms         0.064
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     235
_refine_ls_number_reflns         3426
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0378
_refine_ls_R_factor_gt           0.0336
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0342P)^2^+2.0747P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0802
_refine_ls_wR_factor_ref         0.0820
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3125
_reflns_number_total             3426
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6cc00435k2.cif
_cod_data_source_block           exp_140_autored
_cod_depositor_comments
'Adding full bibliography for 7135696--7135704.cif.'
_cod_database_code               7135699
_shelx_shelxl_version_number     2018/3
_chemical_oxdiff_formula         C24H18Fe2
_chemical_oxdiff_usercomment     CHCl3
_shelx_estimated_absorpt_t_max   0.618
_shelx_estimated_absorpt_t_min   0.225
_diffrn_oxdiff_digest_hkl
;
439a0b0a8740c2b92e59fdbd70898009da481f
;
_diffrn_oxdiff_digest_od_ed
;

;
_diffrn_oxdiff_measurement_exp_name exp_140.par
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C005(H005), C006(H006), C008(H008), C00A(H00A), C00B(H00B), C00D(H00D),
 C00F(H00F), C00H(H00H), C00I(H00I), C00J(H00J), C00K(H00K), C00L(H00L),
 C00M(H00M), C00N(H00N), C00O(H00O), C00P(H00P)
2.b :
 C00G(H00G), C00Q(H00Q)
;
_shelx_res_checksum              94296
_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 1.859
_oxdiff_exptl_absorpt_empirical_full_min 0.689