Boron Tribromide-Assisted Chiral Phosphoric Acid Catalyst for a Highly Enantioselective Diels-Alder Reaction of 1,2-Dihydropyridines.
Hatano, Manabu; Goto, Yuta; Izumiseki, Atsuto; Akakura, Matsujiro; Ishihara, Kazuaki; Journal of the American Chemical Society 137 (2015) 13472–13475; doi:10.1021/jacs.5b08693

data_4129605
_publ_section_title
;
 Boron Tribromide-Assisted Chiral Phosphoric Acid Catalyst for a Highly
 Enantioselective Diels-Alder Reaction of 1,2-Dihydropyridines.
;
_journal_issue                   42
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13472
_journal_page_last               13475
_journal_paper_doi               10.1021/jacs.5b08693
_journal_volume                  137
_journal_year                    2015
_chemical_absolute_configuration (3S,3aS,5R,6R,6aR)
_chemical_formula_sum            'C9 H8 Br F3 O2'
_chemical_formula_weight         285.06
_chemical_name_common
;
(3S,3aS,5R,6R,6aR)-6-Bromo-3-(trifluoromethyl)hexahydro
-2H-3,5-methanocyclopenta[b]furan-2-one
;
_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'
_atom_sites_solution_hydrogens   difmap
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.365(2)
_cell_length_b                   12.061(4)
_cell_length_c                   12.520(4)
_cell_measurement_temperature    93(2)
_cell_volume                     961.1(5)
_computing_cell_refinement       'Rigaku CrystalClear'
_computing_data_collection       'Rigaku CrystalClear'
_computing_data_reduction        'Rigaku CrystalClear'
_computing_molecular_graphics    'Rigaku CrystalStructure'
_computing_publication_material  'Rigaku CrystalStructure'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'Rigaku CrystalStructure'
_diffrn_ambient_temperature      93(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'PILATUS 200K area detector'
_diffrn_measurement_method       'phi and omega scan'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0387
_diffrn_reflns_av_unetI/netI     0.0415
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            8227
_diffrn_reflns_point_group_measured_fraction_full 0.984
_diffrn_reflns_point_group_measured_fraction_max 0.982
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.480
_diffrn_reflns_theta_min         3.254
_exptl_absorpt_coefficient_mu    4.298
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'Rigaku CrystalClear'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.970
_exptl_crystal_description       prism
_exptl_crystal_F_000             560
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.100
_exptl_transmission_factor_max   1.000
_exptl_transmission_factor_min   0.854
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.243
_refine_diff_density_rms         0.056
_refine_ls_abs_structure_details
;
 Flack x determined using 753 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.005(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.862
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     168
_refine_ls_number_reflns         2163
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.862
_refine_ls_R_factor_all          0.0192
_refine_ls_R_factor_gt           0.0173
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0089P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0360
_refine_ls_wR_factor_ref         0.0362
_reflns_Friedel_coverage         0.675
_reflns_Friedel_fraction_full    0.967
_reflns_Friedel_fraction_max     0.961
_reflns_number_gt                1962
_reflns_number_total             2163
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja5b08693_si_002.cif
_cod_data_source_block           CrystalClear
_cod_database_code               4129605
_shelx_estimated_absorpt_t_min   0.480
_shelx_estimated_absorpt_t_max   0.673
_shelxl_version_number           2014/6
_shelx_res_checksum              34224
_shelx_hkl_checksum              79554