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_1504948
_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            'C32 H30 N2 O4'
_chemical_formula_weight         506.58
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                91.653(5)
_cell_angle_beta                 96.063(5)
_cell_angle_gamma                111.856(5)
_cell_formula_units_Z            2
_cell_length_a                   10.7050(2)
_cell_length_b                   11.0380(3)
_cell_length_c                   12.9200(5)
_cell_measurement_reflns_used    6521
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      62.5581
_cell_measurement_theta_min      4.3138
_cell_volume                     1405.14(9)
_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 0.958
_diffrn_measured_fraction_theta_max 0.958
_diffrn_measurement_device_type  'Gemini S Ultra'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'Ultra (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0212
_diffrn_reflns_av_sigmaI/netI    0.0200
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            8855
_diffrn_reflns_theta_full        61.16
_diffrn_reflns_theta_max         61.16
_diffrn_reflns_theta_min         4.33
_exptl_absorpt_coefficient_mu    0.635
_exptl_absorpt_correction_T_max  0.8626
_exptl_absorpt_correction_T_min  0.7945
_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    1.197
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             536
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.332
_refine_diff_density_min         -0.170
_refine_diff_density_rms         0.039
_refine_ls_extinction_coef       0.0176(9)
_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     348
_refine_ls_number_reflns         4129
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0664
_refine_ls_R_factor_gt           0.0568
_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^)+(0.0209P)^2^+0.9801P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1191
_refine_ls_wR_factor_ref         0.1229
_reflns_number_gt                3352
_reflns_number_total             4129
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol802177s_si_003.cif
_cod_data_source_block           080630-cu
_cod_original_cell_volume        1405.14(7)
_cod_database_code               1504948