Synthesis of symmetrical and unsymmetrical cyclic diborenes via NHC-directed C–H borylation
Mihm, Cornelius; Kar, Sourav; Sachs, Andreas; Duwe, Dario; Dewhurst, Rian D.; Braunschweig, Holger; Chemical Science 16 (2025) 11637–11643; doi:10.1039/D5SC03150H

data_1574721
_publ_section_title
;
 Synthesis of symmetrical and unsymmetrical cyclic diborenes via
 NHC-directed C--H borylation
;
_journal_issue                   25
_journal_name_full               'Chemical Science'
_journal_page_first              11637
_journal_page_last               11643
_journal_paper_doi               10.1039/D5SC03150H
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'C44 H54 B2 Br2 N4, C7 H8'
_chemical_formula_sum            'C51 H62 B2 Br2 N4'
_chemical_formula_weight         912.48
_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
_atom_sites_solution_secondary   difmap
_audit_creation_date             2024-11-14
_audit_creation_method           'CIF-fill 1.5k (K.Radacki, 2005-24)'
_audit_update_record
;
2025-04-29 deposited with the CCDC.	2025-05-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 91.6920(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.85310(10)
_cell_length_b                   15.44900(10)
_cell_length_c                   37.9294(3)
_cell_measurement_reflns_used    49275
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      74.7860
_cell_measurement_theta_min      3.0730
_cell_volume                     4599.68(8)
_computing_cell_refinement       'CrysAlisPro 1.171.43.142a (Rigaku OD, 2024)'
_computing_data_collection
;
 CrysAlisPro system (CCD 43.128a 64-bit (release 20-06-2024))
;
_computing_data_reduction        'CrysAlisPro 1.171.43.142a (Rigaku OD, 2024)'
_computing_molecular_graphics    'ShelXLe (Huebschle et all, 2011)'
_computing_publication_material  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)''
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 HPA
_diffrn_detector_area_resol_mean 10.0
_diffrn_detector_type            'HyPix Arc150'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_details
;
 List of Runs (angles in degrees, time in seconds):
 --------------------------------------------------------------------------
  1  \w    -92.00 -31.00   0.50    0.25    --  -76.40 112.00  90.00  122
  2  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00  90.00  100
  3  \w     32.00  92.00   0.50    0.25    --   77.02-112.00   0.00  120
  4  \w   -121.00 -86.00   0.50    0.25    --  -74.00 -58.00 154.72   70
  5  \w    -88.00 -14.00   0.50    0.25    --  -60.41 126.00  30.00  148
  6  \w   -117.00 -83.00   0.50    0.25    --  -70.00 -55.00 -14.01   68
  7  \w   -106.00 -71.00   0.50    0.25    --  -58.00 -51.00 108.20   70
  8  \w   -122.00 -87.00   0.50    0.25    --  -74.00 -52.00 -63.49   70
  9  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00  30.00  100
 10  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00 150.00  100
 11  \w   -122.00 -87.00   0.50    0.25    --  -74.00 -53.00  77.99   70
 12  \w   -117.00 -83.00   0.50    0.25    --  -70.00 -55.00-163.86   68
 13  \w   -103.00 -68.00   0.50    0.25    --  -54.00 -50.00  63.44   70
 14  \w   -128.00 -93.00   0.50    0.25    --  -79.50 -50.00-158.23   70
 15  \w   -129.00 -93.00   0.50    0.25    --  -79.50 -48.00-135.95   72
 16  \w   -102.00 -67.00   0.50    0.25    --  -54.00 -52.00 -73.24   70
 17  \w   -128.00 -90.00   0.50    0.25    --  -78.00 -41.00-125.14   76
 18  \w   -115.00 -80.00   0.50    0.25    --  -66.00 -49.00-100.71   70
 19  \w   -130.00 -91.00   0.50    0.25    --  -79.50 -40.00  46.61   78
 20  \w     30.00  56.00   0.50    0.25    --   18.00  60.00-150.47   52
 21  \w   -121.00 -81.00   0.50    0.25    --  -70.00 -37.00  74.56   80
 22  \w     -4.00  22.00   0.50    0.25    --  -10.00  76.00-171.23   52
 23  \w    -99.00 -64.00   0.50    0.25    --  -50.00 -47.00 -59.31   70
 24  \w    -74.00 -39.00   0.50    0.25    --  -26.00 -52.00 126.90   70
 25  \w   -120.00 -86.00   0.50    0.25    --  -74.00 -59.00   9.31   68
 26  \w    -74.00 -39.00   0.50    0.25    --  -26.00 -51.00  73.14   70
 27  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00   0.00  100
 28  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00 -90.00  100
 29  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00-150.00  100
 30  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00 -60.00  100
 31  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00  60.00  100
 32  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00 120.00  100
 33  \w     34.00  85.00   0.50    0.25    --   77.02 -95.00   0.00  102
 34  \w    -91.00 -56.00   0.50    0.25    --  -42.00 -47.00-147.48   70
 35  \w     34.00  85.00   0.50    0.25    --   77.02 -95.00-150.00  102
 36  \w    -78.00 -43.00   0.50    0.25    --  -30.00 -51.00   4.82   70
 37  \w   -126.00 -92.00   0.50    0.25    --  -79.50-123.00-157.56   68
 38  \w    -97.00 -32.00   0.50    0.25    --  -78.00 114.00   4.81  130
 39  \w     32.00  92.00   0.50    0.25    --   77.02-112.00-180.00  120
 40  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00 -30.00  100
 41  \w    -79.00 -44.00   0.50    0.25    --  -30.00 -48.00 -31.22   70
 42  \w     16.00  66.00   0.50    0.25    --   58.86 -95.00 -90.00  100
 43  \w     16.00  66.00   0.50    0.25    --   58.86 -95.00  60.00  100
 44  \w   -116.00 -79.00   0.50    0.25    --  -66.00 -45.00 154.94   74
 45  \w   -126.00 -93.00   0.50    0.25    --  -79.50-121.00 145.05   66
 46  \w   -126.00 -92.00   0.50    0.25    --  -79.50-122.00  51.83   68
 47  \w   -126.00 -92.00   0.50    0.25    --  -79.50-122.00  -1.86   68
 48  \w     30.00  56.00   0.50    0.25    --   18.00  60.00 -58.58   52
 49  \w     59.00  94.00   0.50    0.25    --   46.00  52.00-149.29   70
 50  \w   -125.00 -85.00   0.50    0.25    --  -74.00 -37.00  26.89   80
 51  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00-180.00  100
 52  \w    -92.00 -31.00   0.50    0.25    --  -76.40 112.00-120.00  122
 53  \w   -126.00 -93.00   0.50    0.25    --  -79.50-121.00-118.47   66
 54  \w     42.00  92.00   0.50    0.25    --   84.75 -95.00-120.00  100
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Rigaku XtaLAB Synergy-R'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
;
 CrysAlisPro convention (1999,Acta A55,543-557)
;
_diffrn_orient_matrix_UB_11      0.1185618000
_diffrn_orient_matrix_UB_12      -0.0449457000
_diffrn_orient_matrix_UB_13      0.0274092000
_diffrn_orient_matrix_UB_21      0.1526141000
_diffrn_orient_matrix_UB_22      0.0152420000
_diffrn_orient_matrix_UB_23      -0.0238347000
_diffrn_orient_matrix_UB_31      0.0341349000
_diffrn_orient_matrix_UB_32      0.0877132000
_diffrn_orient_matrix_UB_33      0.0182095000
_diffrn_radiation_monochromator  'multi-layer mirror'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_radiation_xray_symbol    K-L~2,3~
_diffrn_reflns_av_R_equivalents  0.0428
_diffrn_reflns_av_unetI/netI     0.0241
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       47
_diffrn_reflns_limit_l_min       -46
_diffrn_reflns_number            86061
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.982
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         75.214
_diffrn_reflns_theta_min         3.089
_diffrn_source                   'rotating-anode X-ray tube'
_diffrn_source_type              'PhotonJet-R X-ray Source'
_exptl_absorpt_coefficient_mu    2.522
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.673
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
 CrysAlisPro 1.171.43.142a (Rigaku Oxford Diffraction, 2024) 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            colourless
_exptl_crystal_density_diffrn    1.318
_exptl_crystal_description       needle
_exptl_crystal_F_000             1904
_exptl_crystal_preparation
;
 For data collection the crystal was immersed in a film of perfluoropolyether 
 oil, mounted on a polyimide loop and transferred to stream of cold nitrogen 
 (Oxford Cryostream 800).
;
_exptl_crystal_size_max          0.340
_exptl_crystal_size_mid          0.050
_exptl_crystal_size_min          0.030
_refine_diff_density_max         0.864
_refine_diff_density_min         -0.506
_refine_diff_density_rms         0.074
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.139
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     508
_refine_ls_number_reflns         9333
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.139
_refine_ls_R_factor_all          0.0436
_refine_ls_R_factor_gt           0.0388
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 w=1/[\s^2^(Fo^2^)+(0.0276P)^2^+11.8243P] where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0992
_refine_ls_wR_factor_ref         0.1011
_reflns_Friedel_coverage         0.000
_reflns_number_gt                8419
_reflns_number_total             9333
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc03150h2.cif
_cod_data_source_block           diborane_2
_cod_depositor_comments
'Adding full bibliography for 1574720--1574725.cif.'
_cod_original_cell_volume        4599.69(8)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1574721
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.481
_shelx_estimated_absorpt_t_max   0.928
_shelx_res_checksum              36289