Highly enantioselective synthesis of silahelicenes using Ir-catalyzed [2+2+2] cycloaddition
Takanori Shibata; Toshifumi Uchiyama; Yusuke Yoshinami; Satoshi Takayasu; Kyoji Tsuchikama; Kohei Endo; Chem.Commun. 48 (2012) 1311–; doi:10.1039/c1cc16762f

data_7107242
_publ_section_title
;
 Highly enantioselective synthesis of silahelicenes using Ir-catalyzed
 [2+2+2] cycloaddition
;
_journal_name_full               Chem.Commun.
_journal_page_first              1311
_journal_paper_doi               10.1039/c1cc16762f
_journal_volume                  48
_journal_year                    2012
_chemical_formula_moiety         'C52 H44 O4 Si2'
_chemical_formula_sum            'C52 H44 O4 Si2'
_chemical_formula_weight         789.09
_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
_cell_angle_alpha                90.0000
_cell_angle_beta                 90.0000
_cell_angle_gamma                90.0000
_cell_formula_units_Z            4
_cell_length_a                   10.7414(12)
_cell_length_b                   12.1903(12)
_cell_length_c                   32.074(3)
_cell_measurement_reflns_used    36798
_cell_measurement_temperature    123
_cell_measurement_theta_max      27.50
_cell_measurement_theta_min      3.04
_cell_volume                     4199.8(7)
_computing_cell_refinement       'RAPID AUTO'
_computing_data_collection       'RAPID AUTO (Rigaku, ????)'
_computing_data_reduction        'RAPID AUTO'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'Superflip (Palatinus, et al., 2007)'
_diffrn_ambient_temperature      123
_diffrn_detector_area_resol_mean 10.000
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0551
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            62484
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.131
_exptl_absorpt_correction_T_max  0.974
_exptl_absorpt_correction_T_min  0.954
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'NUMABS (Rigaku, 1999)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.248
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1664.00
_exptl_crystal_size_max          0.600
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.200
_refine_diff_density_max         2.050
_refine_diff_density_min         -0.610
_refine_ls_abs_structure_details
'Flack, H. D. (1983), Acta Cryst. A39, 876-881. 4245 Friedel Pairs'
_refine_ls_abs_structure_Flack   -0.04(12)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.290
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     523
_refine_ls_number_reflns         9588
_refine_ls_number_restraints     0
_refine_ls_R_factor_gt           0.0576
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1727
_reflns_number_gt                8386
_reflns_number_total             9588
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            c1cc16762f.txt
_cod_data_source_block           Shibata-sat
_cod_original_cell_volume        4199.9(8)
_cod_database_code               7107242