Pyridine-boryl radicals-mediated reductive homocoupling of para-quinone methides
Wang, Yan-Bo; Cui, Yan-Zhao; Li, He; Liu, Huiyi; Yuan, Hao-Qi; Zhou, Hao-Tian; Wang, Xiao-Sai; Organic & Biomolecular Chemistry  (2025) –; doi:10.1039/D6OB00078A

data_7161083
_publ_section_title
;
 Pyridine-boryl radical-mediated reductive homocoupling of
 <i>para</i>-quinone methides.
;
_journal_issue                   15
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3295
_journal_page_last               3300
_journal_paper_doi               10.1039/d6ob00078a
_journal_volume                  24
_journal_year                    2026
_chemical_formula_moiety         'C42 H54 O2'
_chemical_formula_sum            'C42 H54 O2'
_chemical_formula_weight         590.85
_chemical_name_systematic
4,4'-(1,2-diphenylethane-1,2-diyl)bis(2,6-di-tert-butylphenol)
_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     dual
_atom_sites_solution_secondary   difmap
_audit_creation_date             2026-01-13
_audit_creation_method
;
Olex2 1.5
(compiled 2022.04.07 svn.rca3783a0 for OlexSys, GUI svn.r6498)
;
_audit_update_record
;
2026-01-13 deposited with the CCDC.	2026-03-20 downloaded from the CCDC.
;
_cell_angle_alpha                79.360(3)
_cell_angle_beta                 79.696(3)
_cell_angle_gamma                89.653(3)
_cell_formula_units_Z            2
_cell_length_a                   10.5638(10)
_cell_length_b                   12.2180(11)
_cell_length_c                   13.9601(14)
_cell_measurement_reflns_used    4841
_cell_measurement_temperature    173
_cell_measurement_theta_max      26.385
_cell_measurement_theta_min      2.473
_cell_volume                     1741.6(3)
_computing_cell_refinement       'SAINT V8.40B (Bruker, 2016)'
_computing_data_collection       'Bruker D8 Venture diffractometer'
_computing_data_reduction        'SAINT V8.40B (Bruker, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2025/1 (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      173.0
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device       'three-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8 Venture_Air'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0975
_diffrn_reflns_av_unetI/netI     0.0904
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            37575
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.391
_diffrn_reflns_theta_min         1.960
_diffrn_source                   'sealed X-ray tube'
_diffrn_source_current           1.4
_diffrn_source_power             0.07
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    0.067
_exptl_absorpt_correction_T_max  0.0962
_exptl_absorpt_correction_T_min  0.0654
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1555 before and 0.0642 after correction.
The Ratio of minimum to maximum transmission is 0.6798.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.127
_exptl_crystal_description       block
_exptl_crystal_F_000             644
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.601
_refine_diff_density_min         -0.424
_refine_diff_density_rms         0.051
_refine_ls_extinction_coef       0.016(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2025/1 (Sheldrick 2025)'
_refine_ls_goodness_of_fit_ref   1.030
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     571
_refine_ls_number_reflns         8700
_refine_ls_number_restraints     464
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.1620
_refine_ls_R_factor_gt           0.0811
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0711P)^2^+1.3510P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1775
_refine_ls_wR_factor_ref         0.2187
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4507
_reflns_number_total             8700
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6ob00078a2.cif
_cod_data_source_block           M13662_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_diffrn_radiation_probe' value 'X-ray' was changed to
'x-ray' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 8170 2020-07-09 18:12:32Z antanas 

 Adding full bibliography for 7161083--7161088.cif.
;
_cod_database_code               7161083
_shelx_shelxl_version_number     2025/1
_shelx_estimated_absorpt_t_max   0.991
_shelx_estimated_absorpt_t_min   0.989
_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, All O(H) groups
2. Restrained distances
 H20C-H1
 2.2 with sigma of 0.01
 H1-H19A
 2.2 with sigma of 0.01
3. Uiso/Uaniso restraints and constraints
C29 \\sim C22 \\sim C23 \\sim C24 \\sim C25 \\sim C26 \\sim C27 \\sim C28 \\sim
C22A \\sim C23A \\sim C24A \\sim C25A \\sim C26A \\sim C27A \\sim C28A: within
2A with sigma of 0.01 and sigma for terminal atoms of 0.02 within 2A
C35 \\sim C36 \\sim C37 \\sim C38 \\sim C36A \\sim C37A \\sim C38A: within 2A
with sigma of 0.01 and sigma for terminal atoms of 0.02 within 2A
C8 \\sim C1 \\sim C2 \\sim C3 \\sim C4 \\sim C5 \\sim C6 \\sim C7 \\sim C1A
\\sim C2A \\sim C3A \\sim C4A \\sim C5A \\sim C6A \\sim C7A: within 2A with
sigma of 0.01 and sigma for terminal atoms of 0.02 within 2A
Uanis(C1A) \\sim Ueq, Uanis(C2A) \\sim Ueq, Uanis(C3A) \\sim Ueq, Uanis(C4A)
\\sim Ueq, Uanis(C5A) \\sim Ueq, Uanis(C6A) \\sim Ueq, Uanis(C7A) \\sim Ueq:
with sigma of 0.01 and sigma for terminal atoms of 0.02
4. Same fragment restrains
{C1A, C2A, C3A, C4A, C5A, C6A, C7A} sigma for 1-2: 0.01, 1-3: 0.01
as in
{C1, C2, C3, C4, C5, C6, C7}
{C35, C36A, C37A, C38A} sigma for 1-2: 0.01, 1-3: 0.01
as in
{C35, C36, C37, C38}
{C22A, C23A, C24A, C25A, C26A, C27A, C28A} sigma for 1-2: 0.01, 1-3: 0.01
as in
{C22, C23, C24, C25, C26, C27, C28}
5. Others
 Sof(C22A)=Sof(H22A)=Sof(C23A)=Sof(C24A)=Sof(H24A)=Sof(C25A)=Sof(H25A)=
 Sof(C26A)=Sof(H26A)=Sof(C27A)=Sof(H27A)=Sof(C28A)=Sof(H28A)=1-FVAR(1)
 Sof(C22)=Sof(H22)=Sof(C23)=Sof(C24)=Sof(H24)=Sof(C25)=Sof(H25)=Sof(C26)=
 Sof(H26)=Sof(C27)=Sof(H27)=Sof(C28)=Sof(H28)=FVAR(1)
 Sof(C1A)=Sof(H1AA)=Sof(C2A)=Sof(C3A)=Sof(H3A)=Sof(C4A)=Sof(H4A)=Sof(C5A)=
 Sof(H5A)=Sof(C6A)=Sof(H6A)=Sof(C7A)=Sof(H7A)=1-FVAR(2)
 Sof(C1)=Sof(H1A)=Sof(C2)=Sof(C3)=Sof(H3)=Sof(C4)=Sof(H4)=Sof(C5)=Sof(H5)=
 Sof(C6)=Sof(H6)=Sof(C7)=Sof(H7)=FVAR(2)
 Sof(C36A)=Sof(H36D)=Sof(H36E)=Sof(H36F)=Sof(C37A)=Sof(H37D)=Sof(H37E)=
 Sof(H37F)=Sof(C38A)=Sof(H38D)=Sof(H38E)=Sof(H38F)=1-FVAR(3)
 Sof(C36)=Sof(H36A)=Sof(H36B)=Sof(H36C)=Sof(C37)=Sof(H37A)=Sof(H37B)=Sof(H37C)=
 Sof(C38)=Sof(H38A)=Sof(H38B)=Sof(H38C)=FVAR(3)
6.a Ternary CH refined with riding coordinates:
 C1(H1A), C1A(H1AA), C22(H22), C22A(H22A)
6.b Aromatic/amide H refined with riding coordinates:
 C9(H9), C13(H13), C3(H3), C4(H4), C5(H5), C6(H6), C7(H7), C3A(H3A), C4A(H4A),
 C5A(H5A), C6A(H6A), C7A(H7A), C30(H30), C34(H34), C24(H24), C25(H25), C26(H26),
  C27(H27), C28(H28), C24A(H24A), C25A(H25A), C26A(H26A), C27A(H27A), C28A(H28A)
6.c Idealised Me refined as rotating group:
 C15(H15A,H15B,H15C), C16(H16A,H16B,H16C), C17(H17A,H17B,H17C), C19(H19A,H19B,
 H19C), C20(H20A,H20B,H20C), C21(H21A,H21B,H21C), C36(H36A,H36B,H36C), C37(H37A,
 H37B,H37C), C38(H38A,H38B,H38C), C40(H40A,H40B,H40C), C41(H41A,H41B,H41C),
 C42(H42A,H42B,H42C), C36A(H36D,H36E,H36F), C37A(H37D,H37E,H37F), C38A(H38D,
 H38E,H38F)
6.d Idealised tetrahedral OH refined as rotating group:
 O1(H1), O2(H2)
;
_shelx_res_checksum              48012
_olex2_submission_special_instructions 'No special instructions were received'