Efficient synthesis of optically active alpha-quaternary amino acids by highly diastereoselective [2,3]-rearrangement of allylic ammonium ylides
Ting-Shun Zhu; Ming-Hua Xu; Chem.Commun. 48 (2012) 7274–; doi:10.1039/c2cc33027j

data_7107993
_publ_section_title
;
 Efficient synthesis of optically active alpha-quaternary amino acids by
 highly diastereoselective [2,3]-rearrangement of allylic ammonium ylides
;
_journal_name_full               Chem.Commun.
_journal_page_first              7274
_journal_paper_doi               10.1039/c2cc33027j
_journal_volume                  48
_journal_year                    2012
_chemical_formula_sum            'C35 H30 Br N O2'
_chemical_formula_weight         576.51
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                80.855(2)
_cell_angle_beta                 76.993(2)
_cell_angle_gamma                80.832(2)
_cell_formula_units_Z            2
_cell_length_a                   9.3964(10)
_cell_length_b                   11.1200(12)
_cell_length_c                   14.1931(16)
_cell_measurement_reflns_used    2416
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      48.271
_cell_measurement_theta_min      4.486
_cell_volume                     1414.8(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_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      293(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_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  0.0316
_diffrn_reflns_av_sigmaI/netI    0.0545
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            7500
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.23
_exptl_absorpt_coefficient_mu    1.485
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.3557
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.353
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             596
_exptl_crystal_size_max          0.369
_exptl_crystal_size_mid          0.311
_exptl_crystal_size_min          0.237
_refine_diff_density_max         0.581
_refine_diff_density_min         -0.508
_refine_diff_density_rms         0.064
_refine_ls_extinction_coef       0.0142(16)
_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   0.901
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     354
_refine_ls_number_reflns         5205
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.901
_refine_ls_R_factor_all          0.0781
_refine_ls_R_factor_gt           0.0524
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0760P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1223
_refine_ls_wR_factor_ref         0.1302
_reflns_number_gt                3259
_reflns_number_total             5205
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2cc33027j.txt
_cod_data_source_block           cd29453
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7107993