Direct assembly of aldehydes, amino esters, and anilines into chiral imidazolidines via Brønsted acid catalyzed asymmetric 1,3-dipolar cycloadditions.
Liu, Wei-Jun; Chen, Xiao-Hua; Gong, Liu-Zhu; Organic letters 10 (2008) 5357–5360; doi:10.1021/ol802177s

data_1504946
_publ_section_title
;
 Direct assembly of aldehydes, amino esters, and anilines into chiral
 imidazolidines via Br\/onsted acid catalyzed asymmetric 1,3-dipolar
 cycloadditions.
;
_journal_issue                   23
_journal_name_full               'Organic letters'
_journal_page_first              5357
_journal_page_last               5360
_journal_paper_doi               10.1021/ol802177s
_journal_volume                  10
_journal_year                    2008
_chemical_formula_sum            'C31 H34 Br2 N2 O5'
_chemical_formula_weight         674.42
_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                90.000(5)
_cell_angle_beta                 90.000(5)
_cell_angle_gamma                90.000(5)
_cell_formula_units_Z            4
_cell_length_a                   9.814(5)
_cell_length_b                   14.667(5)
_cell_length_c                   21.883(5)
_cell_measurement_reflns_used    15302
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      62.5536
_cell_measurement_theta_min      2.0138
_cell_volume                     3150(2)
_computing_cell_refinement       'CrysAlis RED'
_computing_data_collection       'CrysAlis CCD'
_computing_data_reduction        'CrysAlis RED'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 15.9149
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_device_type  'Gemini S Ultra'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'Ultra (Cu) X-ray Source'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0171
_diffrn_reflns_av_sigmaI/netI    0.0118
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            17695
_diffrn_reflns_theta_full        62.64
_diffrn_reflns_theta_max         62.64
_diffrn_reflns_theta_min         3.63
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    3.591
_exptl_absorpt_correction_T_max  0.4330
_exptl_absorpt_correction_T_min  0.2889
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlis RED, Oxford Diffraction Ltd.,
Version 1.171.32.15 (release 10-01-2008 CrysAlis171 .NET)
(compiled Jan 10 2008,16:37:18)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.422
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1376
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.28
_refine_diff_density_max         0.644
_refine_diff_density_min         -0.558
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(2)
_refine_ls_extinction_coef       0.00369(17)
_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   1.000
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     366
_refine_ls_number_reflns         4875
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0495
_refine_ls_R_factor_gt           0.0481
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0064P)^2^+5.5201P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0966
_refine_ls_wR_factor_ref         0.0971
_reflns_number_gt                4654
_reflns_number_total             4875
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol802177s_si_001.cif
_cod_data_source_block           080515-cu
_cod_database_code               1504946