Chiral 2-Aminobenzimidazoles as Recoverable Organocatalysts for the Addition of 1,3-Dicarbonyl Compounds to Nitroalkenes
Diana Almaşi; Diego A. Alonso; Enrique Gómez-Bengoa; Carmen Nájera; Journal of Organic Chemistry 74 (2009) 6163–6168; doi:10.1021/jo9010552

data_4024764
_publ_section_title
;
Chiral 2-Aminobenzimidazoles as Recoverable Organocatalysts for the
Addition of 1,3-Dicarbonyl Compounds to Nitroalkenes
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6163
_journal_page_last               6168
_journal_paper_doi               10.1021/jo9010552
_journal_volume                  74
_journal_year                    2009
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C18 H17 N O4'
_chemical_formula_sum            'C18 H17 N O4'
_chemical_formula_weight         311.33
_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   difmap
_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                   5.673(3)
_cell_length_b                   14.165(8)
_cell_length_c                   20.076(11)
_cell_measurement_reflns_used    456
_cell_measurement_temperature    296(1)
_cell_measurement_theta_max      16.6
_cell_measurement_theta_min      2.5
_cell_volume                     1613.1(15)
_computing_cell_refinement       'Bruker SMART V5.625'
_computing_data_collection       'Bruker SMART V5.625'
_computing_data_reduction        'Bruker SAINT V6.28A'
_computing_molecular_graphics
;
SHELXTL  Rel. 6.12/V (Sheldrick, Acta Cryst. 2008, A64, 112-122)
;
_computing_publication_material
;
SHELX-97 (Sheldrick, Acta Cryst. 2008, A64, 112-122)' 
;
_computing_structure_refinement
;
SHELXL-97 (Sheldrick, Acta Cryst. 2008, A64, 112-122) 
;
_computing_structure_solution
;SIR92 (Altomare, Cascarano, Giacovazzo and Guagliardi, 
J. Appl. Crystallogr. 1993, 26, 343-350.' 
;
_diffrn_ambient_temperature      296(1)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.1882
_diffrn_reflns_av_sigmaI/netI    0.1298
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            13447
_diffrn_reflns_theta_full        25.09
_diffrn_reflns_theta_max         25.09
_diffrn_reflns_theta_min         2.49
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.9955
_exptl_absorpt_correction_T_min  0.8275
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker/Siemens SADABS V2.03'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.282
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.181
_refine_diff_density_min         -0.202
_refine_diff_density_rms         0.055
_refine_ls_extinction_coef       0.034(5)
_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   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     210
_refine_ls_number_reflns         1676
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.1668
_refine_ls_R_factor_gt           0.0661
_refine_ls_shift/su_max          0.028
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0514P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1207
_refine_ls_wR_factor_ref         0.1626
_reflns_number_gt                799
_reflns_number_total             1676
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jo9010552_si_002.cif
_cod_data_source_block           o
_cod_database_code               4024764