A highly efficient asymmetric Michael addition of α,α-disubstituted aldehydes to maleimides catalyzed by primary amine thiourea salt.
Yu, Feng; Jin, Zhichao; Huang, Huicai; Ye, Tingting; Liang, Xinmiao; Ye, Jinxing; Organic & biomolecular chemistry 8 (2010) 4767–4774; doi:10.1039/c0ob00154f

data_7153443
_publ_section_title
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 A highly efficient asymmetric Michael addition of \a,\a-disubstituted
 aldehydes to maleimides catalyzed by primary amine thiourea salt.
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_journal_issue                   20
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              4767
_journal_page_last               4774
_journal_paper_doi               10.1039/c0ob00154f
_journal_volume                  8
_journal_year                    2010
_chemical_absolute_configuration ad
_chemical_formula_sum            'C14 H14 Br N O3'
_chemical_formula_weight         324.17
_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                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.607(3)
_cell_length_b                   10.212(4)
_cell_length_c                   20.641(8)
_cell_measurement_reflns_used    2610
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      53.183
_cell_measurement_theta_min      4.450
_cell_volume                     1392.7(10)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_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  0.0766
_diffrn_reflns_av_sigmaI/netI    0.0671
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            7653
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.97
_exptl_absorpt_coefficient_mu    2.954
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.50343
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.546
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.367
_exptl_crystal_size_mid          0.351
_exptl_crystal_size_min          0.237
_refine_diff_density_max         0.446
_refine_diff_density_min         -0.389
_refine_diff_density_rms         0.078
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.022(13)
_refine_ls_extinction_coef       0.0075(11)
_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   0.913
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     175
_refine_ls_number_reflns         2719
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.913
_refine_ls_R_factor_all          0.0511
_refine_ls_R_factor_gt           0.0398
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0382P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0822
_refine_ls_wR_factor_ref         0.0850
_reflns_number_gt                2135
_reflns_number_total             2719
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0ob00154f.txt
_cod_data_source_block           cd201259
_cod_depositor_comments
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The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
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_cod_original_cell_volume        1392.7(9)
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7153443