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_7135696
_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_absolute_configuration ad
_chemical_formula_moiety         'C35 H29 Fe2 N O2'
_chemical_formula_sum            'C35 H29 Fe2 N O2'
_chemical_formula_weight         607.29
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2025-12-06
_audit_creation_method
;
Olex2 1.5-ac7-018
(compiled 2025.08.06 svn.rb7424aed for Rigaku Oxford Diffraction, GUI svn.r7314)
;
_audit_update_record
;
2026-01-12 deposited with the CCDC.	2026-04-02 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.815(2)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   7.3633(2)
_cell_length_b                   13.9055(4)
_cell_length_c                   13.1255(3)
_cell_measurement_reflns_used    10427
_cell_measurement_temperature    100.00(14)
_cell_measurement_theta_max      78.3990
_cell_measurement_theta_min      3.3370
_cell_volume                     1342.30(6)
_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(14)
_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 0.965
_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    -22.00  27.00   0.50    0.09    --  -48.61  19.00 -60.00   98
  2  \w    -23.00  27.00   0.50    0.09    --  -48.61  19.00-150.00  100
  3  \w    -23.00  26.00   0.50    0.09    --  -48.61  19.00   0.00   98
  4  \w    -21.00  26.00   0.50    0.09    --  -48.61  19.00 120.00   94
  5  \w    -23.00   5.00   0.50    0.09    --   48.61 -19.00 -90.00   56
  6  \w    -24.00  22.00   0.50    0.09    --   48.61 -19.00 -30.00   92
  7  \w     45.00 103.00   0.50    0.34    --  113.25 -77.00  30.00  116
  8  \w    119.00 145.00   0.50    0.34    --  113.25 141.00 -83.00   52
  9  \w     95.00 171.00   0.50    0.34    --  113.25 125.00 -60.00  152
 10  \w    107.00 142.00   0.50    0.34    --  113.25 125.00   0.00   70
 11  \w    153.00 178.00   0.50    0.34    --  113.25 125.00   0.00   50
 12  \w     95.00 178.00   0.50    0.34    --  113.25 125.00  30.00  166
 13  \w    111.00 136.00   0.50    0.34    --  113.25 129.00 104.00   50
 14  \w    141.00 166.00   0.50    0.34    --  113.25  57.00   0.00   50
 15  \w     98.00 130.00   0.50    0.34    --  113.25  57.00   0.00   64
 16  \w     99.00 176.00   0.50    0.34    --  113.25  57.00-180.00  154
 17  \w     50.00 100.00   0.50    0.34    --  113.25-125.00  60.00  100
 18  \w     61.00 101.00   0.50    0.34    --  113.25-129.00  31.00   80
 19  \w     58.00  96.00   0.50    0.09    --   48.61-129.00  31.00   76
 20  \w     63.00 103.00   0.50    0.34    --  113.25 -99.00 -60.00   80
 21  \w     65.00  92.00   0.50    0.34    --  113.25 -99.00-120.00   54
 22  \w     94.00 121.00   0.50    0.34    --  113.25-141.00-140.00   54
 23  \w     57.00 103.00   0.50    0.09    --   48.61-141.00-140.00   92
 24  \w     44.00  70.00   0.50    0.34    --  113.25 -99.00  90.00   52
 25  \w     44.00  95.00   0.50    0.34    --  113.25 -99.00 120.00  102
 26  \w     79.00 104.00   0.50    0.34    --  113.25 -99.00  90.00   50
 27  \w    -83.00 -58.00   0.50    0.09    --  -48.61 141.00 -83.00   50
 28  \w    -86.00 -61.00   0.50    0.34    --  -91.75 141.00 -83.00   50
 29  \w    -59.00 -34.00   0.50    0.09    --  -48.61 129.00 104.00   50
 30  \w    -65.00 -19.00   0.50    0.34    --  -91.75  57.00 -90.00   92
 31  \w    -64.00 -25.00   0.50    0.34    --  -91.75  57.00-120.00   78
 32  \w   -160.00 -83.00   0.50    0.34    --  -91.75 -19.00 -30.00  154
 33  \w   -161.00-124.00   0.50    0.34    --  -91.75 -57.00 -60.00   74
 34  \w   -110.00 -78.00   0.50    0.34    --  -91.75 -57.00 -60.00   64
 35  \w   -109.00 -79.00   0.50    0.09    --  -48.61-129.00  31.00   60
 36  \w   -156.00 -99.00   0.50    0.34    --  -91.75-129.00  31.00  114
 37  \w   -161.00 -91.00   0.50    0.34    --  -91.75 -99.00 150.00  140
 38  \w   -160.00-128.00   0.50    0.34    --  -91.75 -99.00 -30.00   64
 39  \w   -163.00-108.00   0.50    0.34    --  -91.75 -99.00 -60.00  110
 40  \w   -120.00 -93.00   0.50    0.34    --  -91.75 -99.00 -30.00   54
 41  \w   -113.00 -63.00   0.50    0.09    --  -48.61-141.00-140.00  100
 42  \w   -133.00-108.00   0.50    0.34    --  -91.75-141.00-140.00   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      -0.0339538000
_diffrn_orient_matrix_UB_12      -0.0410669000
_diffrn_orient_matrix_UB_13      -0.1083927000
_diffrn_orient_matrix_UB_21      0.0043354000
_diffrn_orient_matrix_UB_22      -0.1028298000
_diffrn_orient_matrix_UB_23      0.0436920000
_diffrn_orient_matrix_UB_31      -0.2065071000
_diffrn_orient_matrix_UB_32      0.0045657000
_diffrn_orient_matrix_UB_33      0.0128008000
_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  0.0354
_diffrn_reflns_av_unetI/netI     0.0358
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.965
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            16671
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.936
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         79.435
_diffrn_reflns_theta_min         3.371
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    8.932
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.520
_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 red'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    red
_exptl_crystal_density_diffrn    1.503
_exptl_crystal_description       plate
_exptl_crystal_F_000             628
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: hexane/acetone'
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.309
_refine_diff_density_min         -0.242
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details
;
 Flack x determined using 2285 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.012(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     364
_refine_ls_number_reflns         5468
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0304
_refine_ls_R_factor_gt           0.0291
_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^)+(0.0281P)^2^+0.7615P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0709
_refine_ls_wR_factor_ref         0.0715
_reflns_Friedel_coverage         0.860
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.904
_reflns_number_gt                5295
_reflns_number_total             5468
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6cc00435k2.cif
_cod_data_source_block           fc-5c-meso_autored
_cod_depositor_comments
'Adding full bibliography for 7135696--7135704.cif.'
_cod_database_code               7135696
_shelx_shelxl_version_number     2018/3
_chemical_oxdiff_formula         C35H29Fe2NO2
_shelx_estimated_absorpt_t_max   0.616
_shelx_estimated_absorpt_t_min   0.205
_diffrn_oxdiff_digest_hkl
;
431f1a5e43bdcf8cf2eb540517e6c4c5f858ea
;
_diffrn_oxdiff_digest_od_ed
;

;
_diffrn_oxdiff_measurement_exp_name Fc-5c-meso.par
_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:
 C009(H009), C00C(H00C), C00E(H00E), C00F(H00F), C00G(H00G), C00J(H00J),
 C00K(H00K), C00O(H00O), C00Q(H00Q), C00R(H00R), C00S(H00S), C00U(H00U),
 C00V(H00V), C00W(H00W), C00Z(H00Z), C010(H010), C011(H011), C012(H012),
 C013(H013), C014(H014)
2.b Idealised Me refined as rotating group:
 C00P(H00A,H00B,H00D), C00X(H00H,H00I,H00L), C00Y(H00M,H00N,H00P)
;
_shelx_res_checksum              28236
_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 1.283
_oxdiff_exptl_absorpt_empirical_full_min 0.812