Synthesis of [5]Helicenes with a Substituent Exclusively on the Interior Side of the Helix by Metal-catalyzed Cycloisomerization.
Yamamoto, Kosuke; Okazumi, Mieko; Suemune, Hiroshi; Usui, Kazuteru; Organic letters 15 (2013) 1806–1809; doi:10.1021/ol400332j

data_1511882
_publ_section_title
;
 Synthesis of [5]Helicenes with a Substituent Exclusively on the Interior
 Side of the Helix by Metal-catalyzed Cycloisomerization.
;
_journal_issue                   8
_journal_name_full               'Organic letters'
_journal_page_first              1806
_journal_page_last               1809
_journal_paper_doi               10.1021/ol400332j
_journal_volume                  15
_journal_year                    2013
_chemical_formula_sum            'C23 H16 O'
_chemical_formula_weight         308.36
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'APEX2 v2009.11-0'
_cell_angle_alpha                90
_cell_angle_beta                 91.632(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.4251(11)
_cell_length_b                   11.3441(16)
_cell_length_c                   18.176(3)
_cell_measurement_reflns_used    6491
_cell_measurement_temperature    93.(2)
_cell_measurement_theta_max      28.3711
_cell_measurement_theta_min      2.2419
_cell_volume                     1530.4(4)
_computing_cell_refinement       'SAINT V7.68A (Bruker AXS, 2009)'
_computing_data_reduction        'SAINT V7.68A (Bruker AXS, 2009)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      93.(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0173
_diffrn_reflns_av_sigmaI/netI    0.0279
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            7261
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.12
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.98
_exptl_absorpt_correction_T_min  0.80
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2008/1 (Bruker AXS)'
_exptl_crystal_density_diffrn    1.338
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             648
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.119
_refine_diff_density_min         -0.154
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   1.9(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.911
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     435
_refine_ls_number_reflns         4471
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.911
_refine_ls_R_factor_all          0.0290
_refine_ls_R_factor_gt           0.0271
_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^)+(0.0336P)^2^+0.4649P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0655
_refine_ls_wR_factor_ref         0.0666
_reflns_number_gt                4285
_reflns_number_total             4471
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol400332j_si_003.cif
_cod_data_source_block           I
_cod_database_code               1511882