Asymmetric [3 + 2] Cycloaddition of Chiral N-Phosphonyl Imines with Methyl Isocyanoacetate for Accessing to 2-Imidazolines with Switchable Stereoselectivity.
Qiao, Shuo; Wilcox, Cody B.; Unruh, Daniel K.; Jiang, Bo; Li, Guigen; The Journal of organic chemistry  (2017) –; doi:10.1021/acs.joc.6b03068

data_4032370
_publ_section_title
;
 Asymmetric [3 + 2] Cycloaddition of Chiral N-Phosphonyl Imines with
 Methyl Isocyanoacetate for Accessing to 2-Imidazolines with Switchable
 Stereoselectivity.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.6b03068
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_sum            'C23 H35 N4 O3 P'
_chemical_formula_weight         446.52
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_date             2015-07-09T10:18:34-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 104.909(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.9174(14)
_cell_length_b                   20.176(5)
_cell_length_c                   10.449(2)
_cell_measurement_reflns_used    2935
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      22.35
_cell_measurement_theta_min      2.26
_cell_volume                     1205.5(5)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w 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  0.0547
_diffrn_reflns_Laue_measured_fraction_full 1
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            15404
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.994
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.498
_diffrn_reflns_theta_min         2.017
_exptl_absorpt_coefficient_mu    0.145
_exptl_absorpt_correction_T_max  0.7452
_exptl_absorpt_correction_T_min  0.6917
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.23
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             480
_exptl_crystal_size_max          0.105
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.035
_refine_diff_density_max         0.232
_refine_diff_density_min         -0.295
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details
;
 Flack x determined using 1517 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.06(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.003
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     285
_refine_ls_number_reflns         4468
_refine_ls_number_restraints     256
_refine_ls_restrained_S_all      0.982
_refine_ls_R_factor_all          0.0589
_refine_ls_R_factor_gt           0.0424
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0508P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0897
_refine_ls_wR_factor_ref         0.0965
_reflns_number_gt                3720
_reflns_number_total             4468
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo6b03068_si_003.cif
_cod_data_source_block           li15_03_0m_a
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4032370
_shelx_estimated_absorpt_t_min   0.985
_shelx_estimated_absorpt_t_max   0.995
_shelx_res_checksum              4143
_shelx_hkl_checksum              26068