Cooperative N-Heterocyclic Carbene/Lewis Acid Catalysis for Highly Stereoselective Annulation Reactions with Homoenolates
Benoit Cardinal-David; Dustin E. A. Raup; Karl A. Scheidt; Journal of the American Chemical Society 132 (2010) 5345–5347; doi:10.1021/ja910666n

data_4102291
_publ_section_title
;
 Cooperative N-Heterocyclic Carbene/Lewis Acid Catalysis for Highly
 Stereoselective Annulation Reactions with Homoenolates
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5345
_journal_page_last               5347
_journal_paper_doi               10.1021/ja910666n
_journal_volume                  132
_journal_year                    2010
_chemical_formula_sum            'C23 H20 Br'
_chemical_formula_weight         376.30
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.88940(10)
_cell_length_b                   8.36830(10)
_cell_length_c                   34.8423(4)
_cell_measurement_temperature    100(2)
_cell_volume                     1717.18(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0854
_diffrn_reflns_av_sigmaI/netI    0.0387
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       47
_diffrn_reflns_limit_l_min       -49
_diffrn_reflns_number            34263
_diffrn_reflns_theta_full        30.10
_diffrn_reflns_theta_max         30.10
_diffrn_reflns_theta_min         1.17
_exptl_absorpt_coefficient_mu    2.394
_exptl_absorpt_correction_T_max  0.7906
_exptl_absorpt_correction_T_min  0.3819
_exptl_crystal_density_diffrn    1.456
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             772
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.978
_refine_diff_density_min         -0.980
_refine_diff_density_rms         0.148
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.003(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.122
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         5055
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.122
_refine_ls_R_factor_all          0.0349
_refine_ls_R_factor_gt           0.0307
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0546P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0818
_refine_ls_wR_factor_ref         0.0887
_reflns_number_gt                4676
_reflns_number_total             5055
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja910666n_si_001.cif
_cod_data_source_block           n0168_0m
_cod_database_code               4102291