Synthesis of Boriranes by Double Hydroboration Reactions of N-Heterocyclic Carbene Boranes and Dimethyl Acetylenedicarboxylate.
McFadden, Timothy R.; Fang, Cheng; Geib, Steven J.; Merling, Everett; Liu, Peng; Curran, Dennis P.; Journal of the American Chemical Society 139 (2017) 1726–1729; doi:10.1021/jacs.6b09873

data_4125690
_publ_section_title
;
 Synthesis of Boriranes by Double Hydroboration Reactions of
 N-Heterocyclic Carbene Boranes and Dimethyl Acetylenedicarboxylate.
;
_journal_issue                   5
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1726
_journal_page_last               1729
_journal_paper_doi               10.1021/jacs.6b09873
_journal_volume                  139
_journal_year                    2017
_chemical_formula_sum            'C27 H33 B N2 O4'
_chemical_formula_weight         460.36
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   20.4678(7)
_cell_length_b                   7.5827(3)
_cell_length_c                   32.8729(11)
_cell_measurement_reflns_used    3176
_cell_measurement_temperature    230(2)
_cell_measurement_theta_max      48.129
_cell_measurement_theta_min      2.688
_cell_volume                     5101.9(3)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      230(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker Apex II CCD'
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0873
_diffrn_reflns_av_unetI/netI     0.0680
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            41586
_diffrn_reflns_point_group_measured_fraction_full 0.977
_diffrn_reflns_point_group_measured_fraction_max 0.971
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.539
_diffrn_reflns_theta_min         2.688
_diffrn_source                   'Bruker Prospector Ultra with CU IMuS'
_exptl_absorpt_coefficient_mu    0.635
_exptl_absorpt_correction_T_max  0.75
_exptl_absorpt_correction_T_min  0.59
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker Sadabs'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.199
_exptl_crystal_description       plate
_exptl_crystal_F_000             1968
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.620
_refine_diff_density_min         -0.277
_refine_diff_density_rms         0.091
_refine_ls_abs_structure_details
;
 Flack x determined using 2259 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.4(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.649
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     622
_refine_ls_number_reflns         9114
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.649
_refine_ls_R_factor_all          0.1294
_refine_ls_R_factor_gt           0.0964
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0680P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2146
_refine_ls_wR_factor_ref         0.2282
_reflns_Friedel_coverage         0.912
_reflns_Friedel_fraction_full    0.952
_reflns_Friedel_fraction_max     0.944
_reflns_number_gt                6182
_reflns_number_total             9114
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja6b09873_si_005.cif
_cod_data_source_block           mcfadden71316a_a
_cod_database_code               4125690
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              50795
_shelx_hkl_checksum              92596