Efficient C-B Bond Formation Promoted by N-Heterocyclic Carbenes: Synthesis of Tertiary and Quaternary B-Substituted Carbons through Metal-Free Catalytic Boron Conjugate Additions to Cyclic and Acyclic α,β-Unsaturated Carbonyls
Kang-sang Lee; Adil R. Zhugralin; Amir H. Hoveyda; Journal of the American Chemical Society 131 (2009) 7253–7255; doi:10.1021/ja902889s

data_4104469
_publ_section_title
;
 Efficient C-B Bond Formation Promoted by N-Heterocyclic Carbenes:
 Synthesis of Tertiary and Quaternary B-Substituted Carbons through
 Metal-Free Catalytic Boron Conjugate Additions to Cyclic and Acyclic
 \a,\b-Unsaturated Carbonyls
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7253
_journal_page_last               7255
_journal_paper_doi               10.1021/ja902889s
_journal_volume                  131
_journal_year                    2009
_chemical_formula_moiety         'C19 H26 B Br O4'
_chemical_formula_sum            'C19 H26 B Br O4'
_chemical_formula_weight         409.12
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 108.603(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   12.509(3)
_cell_length_b                   32.442(7)
_cell_length_c                   9.963(2)
_cell_measurement_reflns_used    9889
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.25
_cell_measurement_theta_min      2.25
_cell_volume                     3831.9(15)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'Bruker SMART APEX CCD'
_diffrn_measurement_method       '0.3 deg wide \w exposures'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0370
_diffrn_reflns_av_sigmaI/netI    0.0308
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       42
_diffrn_reflns_limit_k_min       -43
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            46848
_diffrn_reflns_theta_full        28.31
_diffrn_reflns_theta_max         28.31
_diffrn_reflns_theta_min         1.72
_exptl_absorpt_coefficient_mu    2.165
_exptl_absorpt_correction_T_max  0.9580
_exptl_absorpt_correction_T_min  0.7811
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.418
_exptl_crystal_density_method    none
_exptl_crystal_description       block
_exptl_crystal_F_000             1696
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.581
_refine_diff_density_min         -0.252
_refine_diff_density_rms         0.071
_refine_ls_extinction_coef       na
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.033
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     607
_refine_ls_number_reflns         9443
_refine_ls_number_restraints     52
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0432
_refine_ls_R_factor_gt           0.0323
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0384P)^2^+1.7356P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0730
_refine_ls_wR_factor_ref         0.0777
_reflns_number_gt                7867
_reflns_number_total             9443
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja902889s_si_005.cif
_cod_data_source_block           C19H26BBrO4
_cod_original_cell_volume        3832.0(15)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4104469