Facile synthesis of enantioenriched Cγ-tetrasubstituted α-amino acid derivatives via an asymmetric nucleophilic addition/protonation cascade.
Duan, Shu-Wen; An, Jing; Chen, Jia-Rong; Xiao, Wen-Jing; Organic letters 13 (2011) 2290–2293; doi:10.1021/ol200550y

data_1502133
_publ_section_title
;
 Facile synthesis of enantioenriched C\g-tetrasubstituted \a-amino acid
 derivatives via an asymmetric nucleophilic addition/protonation cascade.
;
_journal_issue                   9
_journal_name_full               'Organic letters'
_journal_page_first              2290
_journal_page_last               2293
_journal_paper_doi               10.1021/ol200550y
_journal_volume                  13
_journal_year                    2011
_chemical_absolute_configuration unk
_chemical_formula_sum            'C32 H29 Br N2 O7'
_chemical_formula_weight         633.48
_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                   10.7740(6)
_cell_length_b                   14.2273(8)
_cell_length_c                   19.8345(11)
_cell_measurement_reflns_used    7999
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      22.68
_cell_measurement_theta_min      2.37
_cell_volume                     3040.3(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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      298(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_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  0.0283
_diffrn_reflns_av_sigmaI/netI    0.0478
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            28737
_diffrn_reflns_theta_full        28.29
_diffrn_reflns_theta_max         28.29
_diffrn_reflns_theta_min         2.15
_exptl_absorpt_coefficient_mu    1.402
_exptl_absorpt_correction_T_max  0.7669
_exptl_absorpt_correction_T_min  0.6041
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.384
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1304
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.413
_refine_diff_density_min         -0.348
_refine_diff_density_rms         0.041
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.003(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     383
_refine_ls_number_reflns         7448
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0752
_refine_ls_R_factor_gt           0.0438
_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^)+(0.0587P)^2^+0.3229P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1119
_refine_ls_wR_factor_ref         0.1260
_reflns_number_gt                4860
_reflns_number_total             7448
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol200550y_si_001.cif
_cod_data_source_block           101014em
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_absolute_configuration' value ' unk ' changed to 'unk'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_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               1502133