Stereodivergency of triazolium and imidazolium-derived NHCs for catalytic, enantioselective cyclopentane synthesis.
Kaeobamrung, Juthanat; Bode, Jeffrey W.; Organic letters 11 (2009) 677–680; doi:10.1021/ol802739d

data_1503765
_publ_section_title
;
 Stereodivergency of triazolium and imidazolium-derived NHCs for
 catalytic, enantioselective cyclopentane synthesis.
;
_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              677
_journal_page_last               680
_journal_paper_doi               10.1021/ol802739d
_journal_volume                  11
_journal_year                    2009
_chemical_absolute_configuration ad
_chemical_formula_sum            'C18 H21 Br O5'
_chemical_formula_weight         397.26
_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                   6.843(3)
_cell_length_b                   15.583(7)
_cell_length_c                   17.024(7)
_cell_measurement_temperature    293(2)
_cell_volume                     1815.3(14)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.961
_diffrn_measured_fraction_theta_max 0.961
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'Omega scan'
_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  0.2893
_diffrn_reflns_av_sigmaI/netI    0.4238
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            11835
_diffrn_reflns_theta_full        25.51
_diffrn_reflns_theta_max         25.51
_diffrn_reflns_theta_min         1.77
_exptl_absorpt_coefficient_mu    2.288
_exptl_absorpt_correction_T_max  0.397
_exptl_absorpt_correction_T_min  0.109
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'psi scan'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.454
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.465
_refine_diff_density_min         -0.439
_refine_diff_density_rms         0.086
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(3)
_refine_ls_extinction_coef       0.0022(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.756
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     231
_refine_ls_number_reflns         3191
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.756
_refine_ls_R_factor_all          0.2654
_refine_ls_R_factor_gt           0.0673
_refine_ls_shift/su_max          0.100
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0502P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1332
_refine_ls_wR_factor_ref         0.1715
_reflns_number_gt                928
_reflns_number_total             3191
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol802739d_si_005.cif
_cod_data_source_block           b6
_cod_original_cell_volume        1815.3(13)
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               1503765