Enantioselective N-heterocyclic carbene-catalyzed Michael addition to α,β-unsaturated aldehydes by redox oxidation.
Rong, Zi-Qiang; Jia, Min-Qiang; You, Shu-Li; Organic letters 13 (2011) 4080–4083; doi:10.1021/ol201595f

data_1502334
_publ_section_title
;
 Enantioselective N-heterocyclic carbene-catalyzed Michael addition to
 \a,\b-unsaturated aldehydes by redox oxidation.
;
_journal_issue                   15
_journal_name_full               'Organic letters'
_journal_page_first              4080
_journal_page_last               4083
_journal_paper_doi               10.1021/ol201595f
_journal_volume                  13
_journal_year                    2011
_chemical_absolute_configuration ad
_chemical_formula_sum            'C24 H17 Br O3'
_chemical_formula_weight         433.29
_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                   7.6826(7)
_cell_length_b                   11.6731(11)
_cell_length_c                   21.484(2)
_cell_measurement_reflns_used    4645
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      49.736
_cell_measurement_theta_min      5.153
_cell_volume                     1926.7(3)
_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 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0210
_diffrn_reflns_av_sigmaI/netI    0.0477
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            10371
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.90
_exptl_absorpt_coefficient_mu    2.156
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.64415
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.494
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             880
_exptl_crystal_size_max          0.356
_exptl_crystal_size_mid          0.215
_exptl_crystal_size_min          0.179
_refine_diff_density_max         0.384
_refine_diff_density_min         -0.162
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.009(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         3767
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.0334
_refine_ls_R_factor_gt           0.0287
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0288P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0690
_refine_ls_wR_factor_ref         0.0707
_reflns_number_gt                3399
_reflns_number_total             3767
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol201595f_si_002.cif
_cod_data_source_block           cd21189
_cod_depositor_comments
;
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 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               1502334