Chiral boron Lewis acid-catalyzed asymmetric synthesis of 4,5-dihydropyrrolo[1,2-a]quinoxalines
Li, Yuan; Su, Yu-Han; Dong, De-Jun; Wu, Zhao; Tian, Shi-Kai; RSC Advances 3 (2013) 18275–; doi:10.1039/c3ra43248c

data_7239174
_publ_section_title
;
 Chiral boron Lewis acid-catalyzed asymmetric synthesis of
 4,5-dihydropyrrolo[1,2-a]quinoxalines
;
_journal_issue                   40
_journal_name_full               'RSC Advances'
_journal_page_first              18275
_journal_paper_doi               10.1039/c3ra43248c
_journal_volume                  3
_journal_year                    2013
_chemical_absolute_configuration ad
_chemical_formula_sum            'C22 H17 Br N2 O3 S'
_chemical_formula_weight         469.35
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_cell_setting           orthorhombic
_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                   9.0110(3)
_cell_length_b                   10.3134(5)
_cell_length_c                   22.7196(9)
_cell_measurement_reflns_used    1984
_cell_measurement_temperature    290(2)
_cell_measurement_theta_max      29.0197
_cell_measurement_theta_min      2.8795
_cell_volume                     2111.42(15)
_computing_cell_refinement       'CrysAlisPro (Agilent Technologies)'
_computing_data_collection       'CrysAlisPro (Agilent Technologies)'
_computing_data_reduction        'CrysAlisPro (Agilent Technologies)'
_computing_molecular_graphics    'Ortep-3 (L. J. Farrugia, 2001)'
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      290(2)
_diffrn_detector_area_resol_mean 15.9149
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Gemini S Ultra, Agilent Technologies'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0374
_diffrn_reflns_av_sigmaI/netI    0.0668
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            8864
_diffrn_reflns_theta_full        26.36
_diffrn_reflns_theta_max         26.36
_diffrn_reflns_theta_min         2.89
_exptl_absorpt_coefficient_mu    2.071
_exptl_absorpt_correction_T_max  0.5754
_exptl_absorpt_correction_T_min  0.5309
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.21 (release 14-08-2012 CrysAlis171 .NET)
(compiled Sep 14 2012,17:21:16)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_density_diffrn    1.476
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.483
_refine_diff_density_min         -0.424
_refine_diff_density_rms         0.067
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.016(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.023
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     263
_refine_ls_number_reflns         4253
_refine_ls_number_restraints     42
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0928
_refine_ls_R_factor_gt           0.0578
_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^)+(0.0649P)^2^+0.6428P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1241
_refine_ls_wR_factor_ref         0.1422
_reflns_number_gt                2935
_reflns_number_total             4253
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ra43248c.txt
_cod_data_source_block           shelxl
_cod_database_code               7239174