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_7135704
_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         '2(C24 H18 Fe2)'
_chemical_formula_sum            'C48 H36 Fe4'
_chemical_formula_weight         836.17
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   mixed
_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                68.526(3)
_cell_angle_beta                 80.000(2)
_cell_angle_gamma                79.600(3)
_cell_formula_units_Z            1
_cell_length_a                   9.4082(3)
_cell_length_b                   9.7583(3)
_cell_length_c                   10.7276(3)
_cell_measurement_reflns_used    5973
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      76.8640
_cell_measurement_theta_min      4.7840
_cell_volume                     895.21(5)
_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 0.999
_diffrn_measured_fraction_theta_max 0.924
_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    104.00 178.00   0.50    0.46    --  113.25  24.00  84.00  148
  2  \w    135.00 160.00   0.50    0.46    --  113.25  38.00 -30.00   50
  3  \w     51.00 109.00   0.50    0.11    --   48.61  24.00  84.00  116
  4  \w     46.00  74.00   0.50    0.11    --   48.61-125.00 120.00   56
  5  \w     79.00 104.00   0.50    0.46    --  113.25-125.00 -30.00   50
  6  \w     43.00  75.00   0.50    0.46    --  113.25-125.00 -30.00   64
  7  \w     42.00 106.00   0.50    0.46    --  113.25 -99.00-180.00  128
  8  \w     49.00 106.00   0.50    0.46    --  113.25 -99.00-120.00  114
  9  \w     54.00  80.00   0.50    0.46    --  113.25 -99.00 -90.00   52
 10  \w     42.00 106.00   0.50    0.46    --  113.25 -99.00 -30.00  128
 11  \w     79.00 105.00   0.50    0.46    --  113.25 -99.00   0.00   52
 12  \w     42.00 105.00   0.50    0.46    --  113.25 -99.00  30.00  126
 13  \w     67.00 106.00   0.50    0.46    --  113.25 -99.00  90.00   78
 14  \w     64.00  99.00   0.50    0.46    --  113.25 -99.00 150.00   70
 15  \w    -14.00  11.00   0.50    0.11    --   48.61 -19.00 120.00   50
 16  \w    -20.00   5.00   0.50    0.11    --   48.61 -24.00 -79.00   50
 17  \w      5.00  71.00   0.50    0.11    --   48.61 -77.00-120.00  132
 18  \w    -48.00 -22.00   0.50    0.46    --  -91.75  57.00-150.00   52
 19  \w    -64.00 -19.00   0.50    0.46    --  -91.75  57.00 120.00   90
 20  \w    -65.00 -28.00   0.50    0.46    --  -91.75  57.00  90.00   74
 21  \w    -61.00 -24.00   0.50    0.46    --  -91.75  57.00  60.00   74
 22  \w    -22.00  15.00   0.50    0.11    --  -48.61  24.00  84.00   74
 23  \w    -66.00 -23.00   0.50    0.46    --  -91.75  57.00 150.00   86
 24  \w    -65.00 -32.00   0.50    0.46    --  -91.75 125.00  90.00   66
 25  \w    -70.00 -26.00   0.50    0.11    --  -48.61 -77.00-150.00   88
 26  \w   -113.00 -87.00   0.50    0.11    --  -48.61 -77.00-150.00   52
 27  \w   -123.00 -36.00   0.50    0.11    --  -48.61 -24.00 -79.00  174
 28  \w    -85.00 -19.00   0.50    0.46    --  -91.75 125.00 150.00  132
 29  \w   -150.00 -84.00   0.50    0.46    --  -91.75 -24.00 -79.00  132
 30  \w   -158.00 -79.00   0.50    0.46    --  -91.75 -38.00 -30.00  158
 31  \w   -165.00-100.00   0.50    0.46    --  -91.75 -38.00-120.00  130
 32  \w   -162.00-135.00   0.50    0.46    --  -91.75 -38.00-150.00   54
 33  \w   -128.00 -78.00   0.50    0.46    --  -91.75 -38.00-150.00  100
 34  \w   -128.00 -95.00   0.50    0.46    --  -91.75 -99.00-150.00   66
 35  \w   -156.00-131.00   0.50    0.46    --  -91.75 -99.00-150.00   50
;
_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      0.1472573000
_diffrn_orient_matrix_UB_12      0.0615585000
_diffrn_orient_matrix_UB_13      -0.0492885000
_diffrn_orient_matrix_UB_21      -0.0751834000
_diffrn_orient_matrix_UB_22      0.1544542000
_diffrn_orient_matrix_UB_23      -0.0015269000
_diffrn_orient_matrix_UB_31      0.0276983000
_diffrn_orient_matrix_UB_32      -0.0401404000
_diffrn_orient_matrix_UB_33      0.1473641000
_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  0.0258
_diffrn_reflns_av_unetI/netI     0.0285
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.924
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            10034
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.924
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         78.813
_diffrn_reflns_theta_min         4.460
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    12.996
_exptl_absorpt_correction_T_max  0.768
_exptl_absorpt_correction_T_min  0.284
_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    1.551
_exptl_crystal_description       block
_exptl_crystal_F_000             428
_exptl_crystal_preparation       Recrystalization
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.621
_refine_diff_density_min         -0.358
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         3576
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.081
_refine_ls_R_factor_all          0.0319
_refine_ls_R_factor_gt           0.0296
_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^)+(0.0320P)^2^+0.7367P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0749
_refine_ls_wR_factor_ref         0.0759
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3338
_reflns_number_total             3576
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6cc00435k2.cif
_cod_data_source_block           exp_133_autored
_cod_depositor_comments
'Adding full bibliography for 7135696--7135704.cif.'
_cod_database_code               7135704
_shelx_shelxl_version_number     2018/3
_chemical_oxdiff_formula         C24H18Fe2
_chemical_oxdiff_usercomment     Fc-meso-H-Diyne
_shelx_estimated_absorpt_t_max   0.463
_shelx_estimated_absorpt_t_min   0.216
_diffrn_oxdiff_digest_hkl
;
43ec7a1864ed7c697acbaca8fd77897752cec2
;
_diffrn_oxdiff_digest_od_ed
;

;
_diffrn_oxdiff_measurement_exp_name exp_133.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:
 C003(H003), C007(H007), C008(H008), C009(H009), C00A(H00A), C00C(H00C),
 C00D(H00D), C00E(H00E), C00F(H00F), C00G(H00G), C00H(H00H), C00I(H00I),
 C00J(H00J), C00K(H00K), C00M(H00M), C00N(H00N)
2.b :
 C00Q(H00Q)
;
_shelx_res_checksum              3810
_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 1.235
_oxdiff_exptl_absorpt_empirical_full_min 0.834