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_1574722
_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 N4'
_chemical_formula_sum            'C44 H54 B2 N4'
_chemical_formula_weight         660.53
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_date             2023-10-23
_audit_creation_method           'CIF-fill 1.4o (K.Radacki, 2005-23)'
_audit_update_record
;
2025-04-29 deposited with the CCDC.	2025-05-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 104.378(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   13.9101(2)
_cell_length_b                   15.7838(2)
_cell_length_c                   17.8930(3)
_cell_measurement_reflns_used    20892
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      73.2610
_cell_measurement_theta_min      3.6150
_cell_volume                     3805.44(10)
_computing_cell_refinement       'CrysAlisPro 1.171.43.89a (Rigaku OD, 2023)'
_computing_data_collection
;
 CrysAlisPro system (CCD 42.94a 64-bit (release 21-06-2023))
;
_computing_data_reduction        'CrysAlisPro 1.171.43.89a (Rigaku OD, 2023)'
_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 0.994
_diffrn_measurement_details
;
 List of Runs (angles in degrees, time in seconds):
 --------------------------------------------------------------------------
  1  \w    -97.00 -33.00   0.50    0.23    --  -78.00 114.00-126.91  128
  2  \w    -97.00 -37.00   0.50    0.23    --  -79.50 115.00 -73.78  120
  3  \w    -97.00 -46.00   0.50    0.23    --  -78.00 114.00 159.99  102
  4  \w    -54.00 -29.00   0.50    0.23    --  -69.85 103.00 152.00   50
  5  \w    -85.00 -59.00   0.50    0.23    --  -76.37 103.00 152.00   52
  6  \w    -69.00 -44.00   0.50    0.23    --  -60.36 103.00 152.00   50
  7  \w     83.00 109.00   0.50    0.23    --   85.25  14.00 143.76   52
  8  \w    107.00 133.00   0.50    0.23    --   85.25  56.00 177.52   52
  9  \w    100.00 130.00   0.50    0.23    --   85.25  63.00 119.00   60
 10  \w    102.00 132.00   0.50    0.23    --   85.25  43.00  26.63   60
 11  \w    103.00 129.00   0.50    0.23    --   85.25  58.00 -99.69   52
 12  \w    100.00 126.00   0.50    0.23    --   85.25  46.00-108.76   52
 13  \w     61.00  94.00   0.50    0.23    --   46.00  52.00-106.71   66
 14  \w     93.00 126.00   0.50    0.23    --   82.26  15.00 -60.00   66
 15  \w     86.00 120.00   0.50    0.23    --   82.26  15.00   0.00   68
 16  \w    101.00 128.00   0.50    0.23    --   85.25  43.00 156.11   54
 17  \w    100.00 130.00   0.50    0.23    --   85.25  40.00 119.25   60
 18  \w     34.00  59.00   0.50    0.23    --   22.00  58.00 111.73   50
 19  \w     51.00  77.00   0.50    0.23    --   85.25  14.00 143.76   52
 20  \w     57.00  83.00   0.50    0.23    --   85.25  15.00  84.69   52
 21  \w    102.00 128.00   0.50    0.23    --   82.26  15.00-120.00   52
 22  \w    105.00 132.00   0.50    0.23    --   82.26  15.00-150.00   54
 23  \w     96.00 132.00   0.50    0.23    --   85.25 137.00-174.72   72
 24  \w     97.00 130.00   0.50    0.23    --   85.25 124.00-108.04   66
 25  \w    103.00 129.00   0.50    0.23    --   85.25 115.00 -68.65   52
 26  \w    102.00 130.00   0.50    0.23    --   85.25 115.00  61.34   56
 27  \w    100.00 128.00   0.50    0.23    --   85.25 122.00 163.85   56
 28  \w     46.00  71.00   0.50    0.23    --   85.25 -92.00 163.54   50
 29  \w     70.00 100.00   0.50    0.23    --   85.25-126.00  60.02   60
 30  \w     38.00  65.00   0.50    0.23    --   85.25-126.00  60.02   54
 31  \w     46.00  82.00   0.50    0.23    --   85.25-123.00  85.33   72
 32  \w     48.00  74.00   0.50    0.23    --   85.25-121.00 -11.08   52
 33  \w     40.00  77.00   0.50    0.23    --   85.25-137.00-125.27   74
 34  \w     39.00  70.00   0.50    0.23    --   85.25-126.00-149.71   62
 35  \w     44.00  75.00   0.50    0.23    --   85.25-118.00-108.98   62
 36  \w     39.00  89.00   0.50    0.23    --   85.25-138.00 -71.92  100
 37  \w     58.00  93.00   0.50    0.23    --   82.26-112.00 -90.00   70
 38  \w     61.00  93.00   0.50    0.23    --   82.26-112.00 -60.00   64
 39  \w     37.00  62.00   0.50    0.23    --   82.26-112.00-120.00   50
 40  \w     37.00  62.00   0.50    0.23    --   82.26-112.00 -30.00   50
 41  \w     43.00  77.00   0.50    0.23    --   85.25-104.00  -1.75   68
 42  \w     37.00  62.00   0.50    0.23    --   82.26-112.00   0.00   50
 43  \w     55.00  89.00   0.50    0.23    --   82.26-103.00  50.00   68
 44  \w     44.00  83.00   0.50    0.23    --   71.46-103.00  50.00   78
 45  \w     14.00  54.00   0.50    0.23    --   58.75-103.00  50.00   80
 46  \w     43.00  77.00   0.50    0.23    --   85.25-109.00  90.73   68
 47  \w     50.00  97.00   0.50    0.23    --   85.25-114.00 118.69   94
 48  \w     51.00  93.00   0.50    0.23    --   85.25-101.00 130.42   84
 49  \w     50.00  86.00   0.50    0.23    --   85.25 -99.00 150.34   72
 50  \w     48.00  93.00   0.50    0.23    --   85.25-101.00  76.49   90
 51  \w     68.00  93.00   0.50    0.23    --   85.25 -97.00 154.61   50
 52  \w     42.00  92.00   0.50    0.23    --   85.25-100.00   3.74  100
 53  \w     55.00  92.00   0.50    0.23    --   85.25 -96.00 111.22   74
 54  \w     67.00  93.00   0.50    0.23    --   85.25 -97.00  39.69   52
 55  \w     35.00  79.00   0.50    0.23    --   71.46 -95.00 120.00   88
 56  \w     61.00  90.00   0.50    0.23    --   82.26 -95.00 -30.00   58
 57  \w     46.00  93.00   0.50    0.23    --   85.25 -98.00 -59.67   94
 58  \w     66.00  92.00   0.50    0.23    --   85.25-100.00-165.91   52
 59  \w     42.00  93.00   0.50    0.23    --   85.25 -98.00-137.89  102
 60  \w     45.00  70.00   0.50    0.23    --   85.25 -74.00-120.97   50
 61  \w     44.00  69.00   0.50    0.23    --   85.25 -73.00 -69.77   50
 62  \w     43.00  68.00   0.50    0.23    --   85.25 -71.00 -13.29   50
 63  \w   -105.00 -72.00   0.50    0.23    --  -58.00 -50.00  79.61   66
 64  \w   -119.00 -86.00   0.50    0.23    --  -74.00 -60.00 147.71   66
 65  \w    -89.00 -62.00   0.50    0.23    --  -46.00 -47.00  52.46   54
 66  \w   -113.00 -88.00   0.50    0.23    --  -70.00 -57.00  36.41   50
 67  \w   -119.00 -86.00   0.50    0.23    --  -70.00 -46.00  49.41   66
 68  \w   -107.00 -72.00   0.50    0.23    --  -58.00 -50.00 -32.43   70
 69  \w   -130.00 -99.00   0.50    0.23    --  -79.50 -41.00 -36.34   62
 70  \w   -119.00 -94.00   0.50    0.23    --  -79.50 -64.00 -59.34   50
 71  \w   -121.00 -86.00   0.50    0.23    --  -74.00 -56.00 -76.86   70
 72  \w   -129.00 -91.00   0.50    0.23    --  -79.50 -40.00-124.45   76
 73  \w   -130.00 -92.00   0.50    0.23    --  -79.50 -33.00-168.98   76
 74  \w   -122.00 -94.00   0.50    0.23    --  -79.50-119.00-142.27   56
 75  \w   -126.00 -92.00   0.50    0.23    --  -79.50-133.00  48.10   68
;
_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      -0.0677702000
_diffrn_orient_matrix_UB_12      0.0708755000
_diffrn_orient_matrix_UB_13      0.0168843000
_diffrn_orient_matrix_UB_21      -0.0640694000
_diffrn_orient_matrix_UB_22      -0.0060095000
_diffrn_orient_matrix_UB_23      -0.0835005000
_diffrn_orient_matrix_UB_31      -0.0660806000
_diffrn_orient_matrix_UB_32      -0.0668398000
_diffrn_orient_matrix_UB_33      0.0254411000
_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  0.0518
_diffrn_reflns_av_unetI/netI     0.0231
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.994
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            79261
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.994
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         75.347
_diffrn_reflns_theta_min         3.621
_diffrn_source                   'rotating-anode X-ray tube'
_diffrn_source_type              'PhotonJet-R X-ray Source'
_exptl_absorpt_coefficient_mu    0.501
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.839
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
 CrysAlisPro 1.171.43.89a (Rigaku Oxford Diffraction, 2023) 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            green
_exptl_crystal_density_diffrn    1.153
_exptl_crystal_description       block
_exptl_crystal_F_000             1424
_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          0.140
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.080
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.259
_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.048
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     461
_refine_ls_number_reflns         7830
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0775
_refine_ls_R_factor_gt           0.0618
_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^)+(0.0876P)^2^+1.3517P] where P=(Fo^2^+2Fc^2^)/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1687
_refine_ls_wR_factor_ref         0.1802
_reflns_Friedel_coverage         0.000
_reflns_number_gt                6155
_reflns_number_total             7830
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc03150h2.cif
_cod_data_source_block           diborene_5
_cod_depositor_comments
'Adding full bibliography for 1574720--1574725.cif.'
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               1574722
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.933
_shelx_estimated_absorpt_t_max   0.961
_shelx_res_checksum              8852