Asymmetric Michael additions of α-cyanoacetates by soft Lewis acid/hard Brønsted acid catalysis: stereodivergency with bi- vs. monometallic catalysts
Eitel, Simon H.; Jautze, Sascha; Frey, Wolfgang; Peters, René; Chemical Science 4 (2013) 2218–; doi:10.1039/c3sc50419k

data_1514698
_publ_section_title
;
 Asymmetric Michael additions of \a-cyanoacetates by soft Lewis acid/hard
 Br\/onsted acid catalysis: stereodivergency with bi- vs. monometallic
 catalysts
;
_journal_issue                   5
_journal_name_full               'Chemical Science'
_journal_page_first              2218
_journal_paper_doi               10.1039/c3sc50419k
_journal_volume                  4
_journal_year                    2013
_chemical_formula_moiety         'C21 H26 Br N O3'
_chemical_formula_sum            'C21 H26 Br N O3'
_chemical_formula_weight         420.34
_chemical_name_systematic
;
tert-Butyl-2-(4-bromophenyl)-2-cyano-2-(3,3-dimethyl-5-oxocyclo-hexyl)acetate
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_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                 104.963(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   19.981(2)
_cell_length_b                   10.4357(12)
_cell_length_c                   20.133(2)
_cell_measurement_reflns_used    4780
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.5
_cell_measurement_theta_min      1.67
_cell_volume                     4055.7(7)
_computing_cell_refinement       'Bruker APEXII Software Suite, 2008'
_computing_data_collection       'Bruker APEXII Software Suite, 2008'
_computing_data_reduction        'Bruker APEXII Software Suite, 2008'
_computing_molecular_graphics    'SHELXTL-plus, XP (Sheldrick, 1991)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker Kappa APEXII Duo'
_diffrn_measurement_method       'Omega + Phi 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  0.0939
_diffrn_reflns_av_sigmaI/netI    0.0868
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            44613
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         1.67
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.046
_exptl_absorpt_correction_T_max  0.7454
_exptl_absorpt_correction_T_min  0.6649
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Blessing, 1995'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.377
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1744
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.12
_refine_diff_density_max         1.936
_refine_diff_density_min         -0.520
_refine_diff_density_rms         0.106
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.084
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     467
_refine_ls_number_reflns         7529
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.084
_refine_ls_R_factor_all          0.1147
_refine_ls_R_factor_gt           0.0622
_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^)+(0.0475P)^2^+7.9823P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1240
_refine_ls_wR_factor_ref         0.1349
_reflns_number_gt                4780
_reflns_number_total             7529
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3sc50419k.txt
_cod_data_source_block           s1841lm
_cod_original_cell_volume        4055.8(8)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               1514698