Switchable Chemoselectivity for Organocatalytic, Asymmetric Malononitrile Addition to ortho-Formyl Chalcones.
Maity, Sanjay; Saha, Mithu; Hazra, Gurupada; Ghorai, Prasanta; Organic letters 19 (2017) 5872–5875; doi:10.1021/acs.orglett.7b02862

data_1547784
_publ_section_title
;
 Switchable Chemoselectivity for Organocatalytic, Asymmetric Malononitrile
 Addition to ortho-Formyl Chalcones.
;
_journal_issue                   21
_journal_name_full               'Organic letters'
_journal_page_first              5872
_journal_page_last               5875
_journal_paper_doi               10.1021/acs.orglett.7b02862
_journal_volume                  19
_journal_year                    2017
_chemical_absolute_configuration unk
_chemical_formula_sum            'C20 H15 Br N2 O2'
_chemical_formula_weight         395.25
_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
_audit_creation_method           SHELXL-2014/6
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_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.1589(6)
_cell_length_b                   7.3312(8)
_cell_length_c                   38.746(4)
_cell_measurement_reflns_used    9956
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      24.86
_cell_measurement_theta_min      2.83
_cell_volume                     1749.5(3)
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0699
_diffrn_reflns_av_unetI/netI     0.0485
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       49
_diffrn_reflns_limit_l_min       -49
_diffrn_reflns_number            32974
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.205
_diffrn_reflns_theta_min         2.828
_exptl_absorpt_coefficient_mu    2.365
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.501
_exptl_crystal_description       block
_exptl_crystal_F_000             800
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.39
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.386
_refine_diff_density_min         -0.244
_refine_diff_density_rms         0.056
_refine_ls_abs_structure_details
;
 Flack x determined using 1188 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.024(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.033
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     227
_refine_ls_number_reflns         3881
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.0464
_refine_ls_R_factor_gt           0.0318
_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^)+(0.0245P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0552
_refine_ls_wR_factor_ref         0.0581
_reflns_Friedel_coverage         0.691
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.990
_reflns_number_gt                3306
_reflns_number_total             3881
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol7b02862_si_003.cif
_cod_data_source_block           TRYA2
_cod_depositor_comments
'Adding full bibliography for 1547784--1547785.cif.'
_cod_database_code               1547784
_shelxl_version_number           2014/6
_shelx_res_checksum              55208
_shelx_hkl_checksum              92695