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_7135697
_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         'C26 H22 Fe2'
_chemical_formula_sum            'C26 H22 Fe2'
_chemical_formula_weight         446.15
_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   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_update_record
;
2026-01-16 deposited with the CCDC.	2026-04-02 downloaded from the CCDC.
;
_cell_angle_alpha                82.80(2)
_cell_angle_beta                 87.620(19)
_cell_angle_gamma                87.93(2)
_cell_formula_units_Z            2
_cell_length_a                   6.990(4)
_cell_length_b                   10.252(6)
_cell_length_c                   13.881(7)
_cell_measurement_reflns_used    8193
_cell_measurement_temperature    296
_cell_measurement_theta_max      27.45
_cell_measurement_theta_min      3.23
_cell_volume                     985.6(9)
_computing_cell_refinement       'RAPID AUTO'
_computing_data_collection       'RAPID AUTO (Rigaku, ????)'
_computing_data_reduction        'RAPID AUTO'
_computing_molecular_graphics    'CrystalStructure 4.3'
_computing_publication_material  'CrystalStructure 4.3 (Rigaku, 2019)'
_computing_structure_refinement  'SHELXL Version 2018/3 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXT Version 2018/2 (Sheldrick, 2014)'
_diffrn_ambient_temperature      296
_diffrn_detector_area_resol_mean 10.000
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0240
_diffrn_reflns_av_unetI/netI     0.0284
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.989
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            9698
_diffrn_reflns_point_group_measured_fraction_full 0.996
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.452
_diffrn_reflns_theta_min         3.223
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.478
_exptl_absorpt_correction_T_max  0.863
_exptl_absorpt_correction_T_min  0.685
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'ABSCOR (Rigaku, 1995)'
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.503
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       chunk
_exptl_crystal_F_000             460.00
_exptl_crystal_recrystallization_method 'Re-crystallisation from solvent'
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.41
_refine_diff_density_min         -0.30
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.025
_refine_ls_hydrogen_treatment    mixed
_refine_ls_number_parameters     341
_refine_ls_number_reflns         4440
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0375
_refine_ls_R_factor_gt           0.0294
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0378P)^2^+0.3754P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0733
_refine_ls_wR_factor_ref         0.0769
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3698
_reflns_number_total             4440
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            d6cc00435k2.cif
_cod_data_source_block           SawanoRacdineA
_cod_depositor_comments
'Adding full bibliography for 7135696--7135704.cif.'
_cod_database_code               7135697
_shelx_res_checksum              26164