Chiral N-heterocyclic carbene/Lewis acid cooperative catalysis of the reaction of 2-aroylvinylcinnamaldehydes: a switch of the reaction pathway by Lewis acid activation
Zhan-Yong Wang; Ya-Li Ding; Gang Wang; Ying Cheng; Chem.Commun. 52 (2016) 788–; doi:

data_7118482
_publ_section_title
;
 Chiral N-heterocyclic carbene/Lewis acid cooperative catalysis of the
 reaction of 2-aroylvinylcinnamaldehydes: a switch of the reaction pathway
 by Lewis acid activation
;
_journal_name_full               Chem.Commun.
_journal_page_first              788
_journal_volume                  52
_journal_year                    2016
_chemical_formula_moiety         'C36 H26 Br2 O4'
_chemical_formula_sum            'C36 H26 Br2 O4'
_chemical_formula_weight         682.39
_chemical_name_systematic
; 
 ? 
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_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-2014
_audit_update_record
;
2015-10-22 deposited with the CCDC.
2015-11-06 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.5911(18)
_cell_length_b                   13.004(4)
_cell_length_c                   40.623(13)
_cell_measurement_reflns_used    6388
_cell_measurement_temperature    113(2)
_cell_measurement_theta_max      27.85
_cell_measurement_theta_min      2.01
_cell_volume                     2953.6(16)
_computing_cell_refinement       CrystalClear
_computing_data_collection       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_reduction        CrystalClear
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2009)'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      113(2)
_diffrn_detector_area_resol_mean 7.314
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Rigaku Saturn70 CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0538
_diffrn_reflns_av_unetI/netI     0.0732
_diffrn_reflns_laue_measured_fraction_full 0.999
_diffrn_reflns_laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       53
_diffrn_reflns_limit_l_min       -53
_diffrn_reflns_number            23050
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.859
_diffrn_reflns_theta_min         1.860
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.785
_exptl_absorpt_correction_T_max  0.846
_exptl_absorpt_correction_T_min  0.558
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.535
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1376
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.280
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.485
_refine_diff_density_min         -0.466
_refine_diff_density_rms         0.075
_refine_ls_abs_structure_details
; 
 Flack x determined using 1554 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   -0.013(5)
_refine_ls_extinction_coef       0.0047(3)
_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   0.931
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     380
_refine_ls_number_reflns         6972
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.931
_refine_ls_R_factor_all          0.0574
_refine_ls_R_factor_gt           0.0388
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0232P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0641
_refine_ls_wR_factor_ref         0.0701
_reflns_Friedel_coverage         0.724
_reflns_friedel_fraction_full    0.995
_reflns_friedel_fraction_max     0.982
_reflns_number_gt                5148
_reflns_number_total             6972
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c5cc08866f2.cif
_cod_data_source_block           shelxl_a
_cod_original_cell_volume        2953.4(16)
_cod_database_code               7118482
_shelx_estimated_absorpt_t_min   0.469
_shelx_estimated_absorpt_t_max   0.851
_shelxl_version_number           2014-1
_shelx_res_checksum              50517
_shelx_hkl_checksum              77224