Sydnone-Based Approach to Heterohelicenes through 1,3-Dipolar-Cycloadditions.
Yen-Pon, Expédite; Champagne, Pier Alexandre; Plougastel, Lucie; Gabillet, Sandra; Thuéry, Pierre; Johnson, Mizuki; Muller, Gilles; Pieters, Grégory; Taran, Frédéric; Houk, K. N.; Audisio, Davide; Journal of the American Chemical Society 141 (2019) 1435–1440; doi:10.1021/jacs.8b11465

data_4128049
_publ_section_title
;
 Sydnone-Based Approach to Heterohelicenes through
 1,3-Dipolar-Cycloadditions.
;
_journal_issue                   4
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1435
_journal_page_last               1440
_journal_paper_doi               10.1021/jacs.8b11465
_journal_volume                  141
_journal_year                    2019
_chemical_formula_sum            'C27 H16 N2'
_chemical_formula_weight         368.42
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_method           SHELXL-2014
_cell_angle_alpha                90
_cell_angle_beta                 104.082(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.6965(11)
_cell_length_b                   5.8107(4)
_cell_length_c                   18.3992(13)
_cell_measurement_reflns_used    52144
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.68
_cell_measurement_theta_min      2.86
_cell_volume                     1731.4(2)
_computing_cell_refinement       'HKL2000 (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'HKL2000 (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material
'SHELXTL (Sheldrick, 2008); PLATON (Spek, 2003)'
_computing_structure_refinement  'SHELXL (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Nonius Kappa-CCD area-detector diffractometer'
_diffrn_measurement_method
'two \f and four \w scans with 2\% steps (457 frames)'
_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  0.0404
_diffrn_reflns_av_unetI/netI     0.0514
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            52144
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.677
_diffrn_reflns_theta_min         2.862
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'translucent light brown'
_exptl_crystal_density_diffrn    1.413
_exptl_crystal_description       lath
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.21
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.189
_refine_diff_density_min         -0.189
_refine_diff_density_rms         0.036
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         3275
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.020
_refine_ls_R_factor_all          0.0793
_refine_ls_R_factor_gt           0.0464
_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^)+(0.0610P)^2^+0.0138P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1025
_refine_ls_wR_factor_ref         0.1146
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2260
_reflns_number_total             3275
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja8b11465_si_002.cif
_cod_data_source_block           10b
_cod_database_code               4128049
_shelxl_version_number           2014-3
_shelx_res_checksum              92331
_shelx_hkl_checksum              46856