Convergent Strategy for the Synthesis of Oxa-, Thia-, and Selena[5]helicenes by Acetylene-Activated S<sub>N</sub>Ar Reactions.
Hoenig, Samuel M.; Yan, Youmian; Dougherty, Emily A.; Hudson, Reuben; Petovic, Sava; Lee, Christopher K.; Hu, Yusheng; Gomez, Lucas S.; Katz, Jeffrey L.; The Journal of organic chemistry 85 (2020) 4553–4559; doi:10.1021/acs.joc.0c00052

data_4038056
_publ_section_title
;
 Convergent Strategy for the Synthesis of Oxa-, Thia-, and
 Selena[5]helicenes by Acetylene-Activated S<sub>N</sub>Ar Reactions.
;
_journal_issue                   6
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              4553
_journal_page_last               4559
_journal_paper_doi               10.1021/acs.joc.0c00052
_journal_volume                  85
_journal_year                    2020
_chemical_formula_moiety         'C26 H15 F O'
_chemical_formula_sum            'C26 H15 F O'
_chemical_formula_weight         362.38
_chemical_name_common            'oxa[5]helicene 1a'
_chemical_name_systematic
5-fluoro-2-phenylbenzo[5,6]phenanthro[4,3-b]furan
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 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                   7.789(4)
_cell_length_b                   10.907(6)
_cell_length_c                   20.566(13)
_cell_measurement_reflns_used    5329
_cell_measurement_temperature    173
_cell_measurement_theta_max      31.762
_cell_measurement_theta_min      3.214
_cell_volume                     1747.2(17)
_computing_cell_refinement       'SAINT+ Ver. 2016.5-0 (Bruker-AXS, 2016)'
_computing_data_collection       'APEX3 Ver. 2016.5-0 (Bruker-AXS, 2016)'
_computing_data_reduction        'SAINT+ Ver. 2016.5-0 (Bruker-AXS, 2016)'
_computing_molecular_graphics    'OLEX2 (Dolomanov et al., 2009)'
_computing_publication_material  'OLEX2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'XT (Sheldrick, 2015a)'
_diffrn_ambient_temperature      173
_diffrn_detector_area_resol_mean 7.9
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.940
_diffrn_measurement_device_type  'Bruker Photon 50'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0446
_diffrn_reflns_av_unetI/netI     0.0248
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.940
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            28354
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.896
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         31.762
_diffrn_reflns_theta_min         3.214
_diffrn_source                   'sealed X-ray tube'
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.378
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'needle fragment'
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.330
_exptl_crystal_size_mid          0.280
_exptl_crystal_size_min          0.270
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.179
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details
;
 Flack x determined using 2119 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.04(18)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.950
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         5329
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.950
_refine_ls_R_factor_all          0.0416
_refine_ls_R_factor_gt           0.0372
_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^)+(0.1000P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1107
_refine_ls_wR_factor_ref         0.1164
_reflns_Friedel_coverage         0.861
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.850
_reflns_number_gt                4903
_reflns_number_total             5329
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo0c00052_si_002.cif
_cod_data_source_block           JLKIII999_singleOhelix5_Ph_0m_a
_cod_depositor_comments
'Adding full bibliography for 4038056--4038057.cif.'
_cod_original_cell_volume        1747.3(18)
_cod_database_code               4038056
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_max   0.976
_shelx_estimated_absorpt_t_min   0.971
_shelx_res_checksum              71064
_shelx_hkl_checksum              96680