Highly Enantio- and Diastereoselective [4 + 2] Cycloaddition of 5H-oxazol-4-ones with N-Maleimides.
Qiu, Shuai; Lee, Richmond; Zhu, Bo; Coote, Michelle L.; Zhao, Xiaowei; Jiang, Zhiyong; The Journal of organic chemistry 81 (2016) 8061–8069; doi:10.1021/acs.joc.6b01451

data_4037094
_publ_section_title
;
 Highly Enantio- and Diastereoselective [4 + 2] Cycloaddition of
 5H-oxazol-4-ones with N-Maleimides.
;
_journal_issue                   17
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              8061
_journal_page_last               8069
_journal_paper_doi               10.1021/acs.joc.6b01451
_journal_volume                  81
_journal_year                    2016
_chemical_formula_moiety         'C20 H15 Br N2 O4'
_chemical_formula_sum            'C20 H15 Br N2 O4'
_chemical_formula_weight         427.25
_space_group_crystal_system      orthorhombic
_space_group_IT_number           18
_space_group_name_Hall           'P 2bc 2'
_space_group_name_H-M_alt        'P 2 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2016-03-07
_audit_creation_method
;
Olex2 1.2
(compiled 2016.02.19 svn.r3266 for OlexSys, GUI svn.r5155)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   7.8629(5)
_cell_length_b                   17.9726(9)
_cell_length_c                   27.3125(13)
_cell_measurement_reflns_used    1734
_cell_measurement_temperature    291(2)
_cell_measurement_theta_max      21.9070
_cell_measurement_theta_min      2.5190
_cell_volume                     3859.7(4)
_computing_cell_refinement       'CrysAlisPro 1.171.38.41k (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.41k (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.41k (Rigaku OD, 2015)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution
;
Superflip (Palatinus & Chapuis, 2007;Palatinus & van der Lee, 2008;
Palatinus et al., 2012)
;
_diffrn_ambient_temperature      291.15
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 16.2312
_diffrn_detector_type            Eos
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
--------------------------------------------------------------------------
  1  \w    -11.00  22.00   0.30   47.50    --  -15.18 -99.00   0.00  110
  2  \w     -7.00  88.10   0.30   47.50    --   18.07  19.00  90.00  317
  3  \w    -11.00  83.20   0.30   47.50    --   18.07  19.00-180.00  314
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0365854000
_diffrn_orient_matrix_UB_12      -0.0201938000
_diffrn_orient_matrix_UB_13      -0.0196787000
_diffrn_orient_matrix_UB_21      0.0134376000
_diffrn_orient_matrix_UB_22      0.0337270000
_diffrn_orient_matrix_UB_23      -0.0129184000
_diffrn_orient_matrix_UB_31      0.0814424000
_diffrn_orient_matrix_UB_32      0.0035592000
_diffrn_orient_matrix_UB_33      0.0109709000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0683
_diffrn_reflns_av_unetI/netI     0.0884
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            17861
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         26.362
_diffrn_reflns_theta_min         2.266
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    2.157
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.70576
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.41k (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             1728
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.14
_platon_squeeze_details
;
;
_refine_diff_density_max         0.748
_refine_diff_density_min         -0.880
_refine_diff_density_rms         0.076
_refine_ls_abs_structure_details
;
 Flack x determined using 804 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.007(12)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.035
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     477
_refine_ls_number_reflns         7869
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.035
_refine_ls_R_factor_all          0.1584
_refine_ls_R_factor_gt           0.0866
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2205
_refine_ls_wR_factor_ref         0.2640
_reflns_Friedel_coverage         0.775
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                3428
_reflns_number_total             7869
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo6b01451_si_002.cif
_cod_data_source_block           qs24002-2
_cod_depositor_comments
;

2020-08-12
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_formula_moiety     '2(C20 H15 Br N2 O4)'
_cod_original_formula_sum        'C40 H30 Br2 N4 O8'
_cod_original_formula_units_Z    4
_cod_original_formula_weight     854.50
_cod_database_code               4037094
_chemical_oxdiff_formula         C20H20N4O4Br1
_shelx_estimated_absorpt_t_max   0.752
_shelx_estimated_absorpt_t_min   0.724
_reflns_odcompleteness_completeness 99.91
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C8(H8), C9(H9), C8'(H8'), C9'(H9')
2.b Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C5(H5), C6(H6), C16(H16), C17(H17), C18(H18), C19(H19),
 C20(H20), N2(H2A), C2'(H2'), C3'(H3'), C5'(H5'), C6'(H6'), C16'(H16'),
 C20'(H20'), C19'(H19'), C18'(H18'), C17'(H17'), N2'(H2'A)
2.c Fitted hexagon refined as free rotating group:
 C16'(C15',C20',C19',C18',C17')
2.d Idealised Me refined as rotating group:
 C14(H14A,H14B,H14C), C14'(H14D,H14E,H14F)
;
_shelx_res_checksum              97496
_shelx_hkl_checksum              74002
_shelx_shelxl_version_number     2014/7
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.503
_oxdiff_exptl_absorpt_empirical_full_min 0.712