General Asymmetric Hydrogenation of 2-Alkyl- and 2-Aryl-Substituted Quinoxaline Derivatives Catalyzed by Iridium-Difluorphos: Unusual Halide Effect and Synthetic Application
Damien Cartigny; Farouk Berhal; Takuto Nagano; Phannarath Phansavath; Tahar Ayad; Jean-Pierre Genêt; Takashi Ohshima; Kazushi Mashima; Virginie Ratovelomanana-Vidal; Journal of Organic Chemistry 77 (2012) 4544–4556; doi:10.1021/jo300455y

data_4027200
_publ_section_title
;
 General Asymmetric Hydrogenation of 2-Alkyl- and 2-Aryl-Substituted
 Quinoxaline Derivatives Catalyzed by Iridium-Difluorphos: Unusual Halide
 Effect and Synthetic Application
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              4544
_journal_page_last               4556
_journal_paper_doi               10.1021/jo300455y
_journal_volume                  77
_journal_year                    2012
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C23 H24 N2 O2 S'
_chemical_formula_sum            'C23 H24 N2 O2 S'
_chemical_formula_weight         392.50
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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                   8.413(4)
_cell_length_b                   11.5095(13)
_cell_length_c                   21.036(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      33.2
_cell_measurement_theta_min      10.2
_cell_volume                     2036.9(10)
_computing_cell_refinement
'CAD-4 Software:Enraf-Nonius (1989), Delft, The Netherlands'
_computing_data_collection
'CAD-4 Software:Enraf-Nonius (1989), Delft, The Netherlands'
_computing_data_reduction
'XCAD4: Harms, K. & Wocadlo, S. (1995) University of Marburg, Germany.'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1993)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device       'Enraf-Nonius CAD4'
_diffrn_measurement_device_type  Serial
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0447
_diffrn_reflns_av_sigmaI/netI    0.0471
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            8482
_diffrn_reflns_theta_full        75.87
_diffrn_reflns_theta_max         75.87
_diffrn_reflns_theta_min         4.20
_diffrn_standards_decay_%        0.0(3)
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    1.572
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.280
_exptl_crystal_description       block
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.29
_refine_diff_density_max         0.167
_refine_diff_density_min         -0.321
_refine_diff_density_rms         0.031
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.000(17)
_refine_ls_extinction_coef       0.0033(3)
_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   1.032
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     256
_refine_ls_number_reflns         4186
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0442
_refine_ls_R_factor_gt           0.0375
_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^)+(0.0513P)^2^+0.1105P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0972
_refine_ls_wR_factor_ref         0.1023
_reflns_number_gt                3702
_reflns_number_total             4186
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            jo300455y_si_001.cif
_cod_data_source_block           dc531
_cod_original_cell_volume        2037.1(11)
_cod_database_code               4027200