Enantioselective alpha-amination of 1,3-dicarbonyl compounds using squaramide derivatives as hydrogen bonding catalysts.
Konishi, Hideyuki; Lam, Tin Yiu; Malerich, Jeremiah P.; Rawal, Viresh H.; Organic letters 12 (2010) 2028–2031; doi:10.1021/ol1005104

data_1502943
_publ_section_title
;
 Enantioselective alpha-amination of 1,3-dicarbonyl compounds using
 squaramide derivatives as hydrogen bonding catalysts.
;
_journal_issue                   9
_journal_name_full               'Organic letters'
_journal_page_first              2028
_journal_page_last               2031
_journal_paper_doi               10.1021/ol1005104
_journal_volume                  12
_journal_year                    2010
_chemical_absolute_configuration rm
_chemical_formula_sum            'C18 H24 N2 O7'
_chemical_formula_weight         380.39
_space_group_IT_number           4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 92.499(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.8090(16)
_cell_length_b                   9.2002(17)
_cell_length_c                   11.103(2)
_cell_measurement_reflns_used    1024
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.29
_cell_measurement_theta_min      1.84
_cell_volume                     899.0(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.972
_diffrn_measured_fraction_theta_max 0.972
_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  0.0260
_diffrn_reflns_av_sigmaI/netI    0.0391
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            10783
_diffrn_reflns_theta_full        28.29
_diffrn_reflns_theta_max         28.29
_diffrn_reflns_theta_min         1.84
_exptl_absorpt_coefficient_mu    0.109
_exptl_absorpt_correction_T_max  0.9578
_exptl_absorpt_correction_T_min  0.9578
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
absorption corrections were made based on correspondance of
equivalent intensities usingprogram SADABS (G. Sheldrick, Bruker 
Analytical X-ray Systems, Madison, WI)
;
_exptl_crystal_density_diffrn    1.405
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             404
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.308
_refine_diff_density_min         -0.201
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.2(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.925
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     248
_refine_ls_number_reflns         4237
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.925
_refine_ls_R_factor_all          0.0411
_refine_ls_R_factor_gt           0.0389
_refine_ls_shift/su_max          0.016
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0655P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0934
_refine_ls_wR_factor_ref         0.0947
_reflns_number_gt                3966
_reflns_number_total             4237
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol1005104_si_002.cif
_cod_data_source_block           lam02s
_cod_original_sg_symbol_H-M      P21
_cod_database_code               1502943