Asymmetric Synthesis of Spirocyclopentane Oxindoles Containing Four Consecutive Stereocenters and Quaternary α-Nitro Esters via Organocatalytic Enantioselective Michael-Michael Cascade Reactions.
Chaudhari, Prakash D.; Hong, Bor-Cherng; Wen, Chao-Lin; Lee, Gene-Hsiang; ACS omega 4 (2019) 655–667; doi:10.1021/acsomega.8b03049

data_4514951
_publ_section_title
;
 Asymmetric Synthesis of Spirocyclopentane Oxindoles Containing Four
 Consecutive Stereocenters and Quaternary \a-Nitro Esters via
 Organocatalytic Enantioselective Michael-Michael Cascade Reactions.
;
_journal_issue                   1
_journal_name_full               'ACS omega'
_journal_page_first              655
_journal_page_last               667
_journal_paper_doi               10.1021/acsomega.8b03049
_journal_volume                  4
_journal_year                    2019
_chemical_absolute_configuration ad
_chemical_formula_sum            'C20 H18 Br N3 O5'
_chemical_formula_weight         460.28
_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-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.88470(10)
_cell_length_b                   10.0526(2)
_cell_length_c                   31.9302(7)
_cell_measurement_reflns_used    9919
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      75.04
_cell_measurement_theta_min      2.77
_cell_volume                     1888.88(6)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Bruker D8 VENTURE'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0190
_diffrn_reflns_av_unetI/netI     0.0238
_diffrn_reflns_Laue_measured_fraction_full 0.995
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            10463
_diffrn_reflns_point_group_measured_fraction_full 0.994
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         74.982
_diffrn_reflns_theta_min         2.768
_exptl_absorpt_coefficient_mu    3.314
_exptl_absorpt_correction_T_max  0.7539
_exptl_absorpt_correction_T_min  0.5660
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker, 2016)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.619
_exptl_crystal_description       needle
_exptl_crystal_F_000             936
_exptl_crystal_size_max          0.271
_exptl_crystal_size_mid          0.095
_exptl_crystal_size_min          0.081
_refine_diff_density_max         0.414
_refine_diff_density_min         -0.293
_refine_diff_density_rms         0.043
_refine_ls_abs_structure_details
; 
 Flack x determined using 1548 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.030(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.091
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     263
_refine_ls_number_reflns         3864
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.091
_refine_ls_R_factor_all          0.0232
_refine_ls_R_factor_gt           0.0230
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0282P)^2^+0.4775P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0591
_refine_ls_wR_factor_ref         0.0592
_reflns_Friedel_coverage         0.698
_reflns_Friedel_fraction_full    0.992
_reflns_Friedel_fraction_max     0.983
_reflns_number_gt                3832
_reflns_number_total             3864
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ao8b03049_si_011.cif
_cod_data_source_block           ic18876
_cod_database_code               4514951
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.467
_shelx_estimated_absorpt_t_max   0.775
_shelx_res_checksum              47985
_shelx_hkl_checksum              28810