Synthesis of Pyrroles through a 4π-Electrocyclic Ring-Closure Reaction of 1-Azapentadienyl Cations
Rishikesh Narayan; Roland Fröhlich; Ernst-Ulrich Würthwein; Journal of Organic Chemistry 77 (2012) 1868–1879; doi:10.1021/jo202477h

data_4026980
_publ_section_title
;
 Synthesis of Pyrroles through a 4\p-Electrocyclic Ring-Closure Reaction
 of 1-Azapentadienyl Cations
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              1868
_journal_page_last               1879
_journal_paper_doi               10.1021/jo202477h
_journal_volume                  77
_journal_year                    2012
_chemical_formula_sum            'C19 H20 N2'
_chemical_formula_weight         276.37
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 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                 99.461(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   18.0934(3)
_cell_length_b                   8.1573(2)
_cell_length_c                   21.2642(4)
_cell_measurement_reflns_used    3445
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      27.88
_cell_measurement_theta_min      4.08
_cell_volume                     3095.76(11)
_computing_cell_refinement       'Collect (Nonius B.V., 1998)'
_computing_data_collection       'Collect (Nonius B.V., 1998)'
_computing_data_reduction        'Denzo-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'XP (BrukerAXS, 2000)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      223(2)
_diffrn_measured_fraction_theta_full 0.982
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'Nonius KappaCCD APEXII'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_monochromator  'Montel mirror'
_diffrn_radiation_source         'rotating anode Nonius FR591'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.045
_diffrn_reflns_av_sigmaI/netI    0.0318
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       -21
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            11067
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         4.14
_exptl_absorpt_coefficient_mu    0.070
_exptl_absorpt_correction_T_max  0.9951
_exptl_absorpt_correction_T_min  0.9794
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'Denzo (Otwinowski, Borek, Majewski & Minor, 2003)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.186
_exptl_crystal_description       plate
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.190
_refine_diff_density_rms         0.033
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     193
_refine_ls_number_reflns         2683
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0600
_refine_ls_R_factor_gt           0.0515
_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^)+(0.0575P)^2^+3.0656P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1299
_refine_ls_wR_factor_ref         0.1381
_reflns_number_gt                2291
_reflns_number_total             2683
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202477h_si_001.cif
_cod_data_source_block           wue5963
_cod_database_code               4026980