Synthesis of 2,2-Difluorinated 4-Isoflavanols/4-Thioisoflavanols via a Base-Catalyzed [4 + 2] Annulation Reaction of gem-Difluoroolefins.
Li, Jiaheng; Xu, Cong; Wei, Na; Wang, Mang; The Journal of organic chemistry 82 (2017) 11348–11357; doi:10.1021/acs.joc.7b01635

data_4033006
_publ_section_title
;
 Synthesis of 2,2-Difluorinated 4-Isoflavanols/4-Thioisoflavanols via a
 Base-Catalyzed [4 + 2] Annulation Reaction of gem-Difluoroolefins.
;
_journal_issue                   21
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              11348
_journal_page_last               11357
_journal_paper_doi               10.1021/acs.joc.7b01635
_journal_volume                  82
_journal_year                    2017
_chemical_formula_moiety         'C15 H11 F2 N O4'
_chemical_formula_sum            'C15 H11 F2 N O4'
_chemical_formula_weight         307.25
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_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                 98.250(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.9896(14)
_cell_length_b                   8.0336(9)
_cell_length_c                   14.0539(16)
_cell_measurement_reflns_used    9962
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      28.272
_cell_measurement_theta_min      2.407
_cell_volume                     1339.7(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  MoK\a
_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  0.0366
_diffrn_reflns_av_sigmaI/netI    0.0366
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            9449
_diffrn_reflns_theta_full        28.37
_diffrn_reflns_theta_max         28.37
_diffrn_reflns_theta_min         2.09
_exptl_absorpt_coefficient_mu    0.129
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.523
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             632
_exptl_crystal_size_max          0.589
_exptl_crystal_size_mid          0.234
_exptl_crystal_size_min          0.192
_refine_diff_density_max         0.298
_refine_diff_density_min         -0.237
_refine_diff_density_rms         0.055
_refine_ls_extinction_coef       0.021(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   1.037
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     201
_refine_ls_number_reflns         3353
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0550
_refine_ls_R_factor_gt           0.0440
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0578P)^2^+0.2962P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1129
_refine_ls_wR_factor_ref         0.1207
_reflns_number_gt                2707
_reflns_number_total             3353
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo7b01635_si_002.cif
_cod_data_source_block           ljh11
_cod_depositor_comments          'Adding full bibliography for 4033006.cif.'
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4033006