NHC-catalyzed enantioselective [2 + 2] and [2 + 2 + 2] cycloadditions of ketenes with isothiocyanates.
Wang, Xiao-Na; Shen, Li-Tao; Ye, Song; Organic letters 13 (2011) 6382–6385; doi:10.1021/ol202688h

data_1502593
_publ_section_title
;
 NHC-catalyzed enantioselective [2 + 2] and [2 + 2 + 2] cycloadditions of
 ketenes with isothiocyanates.
;
_journal_issue                   24
_journal_name_full               'Organic letters'
_journal_page_first              6382
_journal_page_last               6385
_journal_paper_doi               10.1021/ol202688h
_journal_volume                  13
_journal_year                    2011
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C16 H12 N2 O3 S'
_chemical_formula_sum            'C16 H12 N2 O3 S'
_chemical_formula_weight         312.34
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                108.255(5)
_cell_angle_beta                 96.360(5)
_cell_angle_gamma                91.162(3)
_cell_formula_units_Z            4
_cell_length_a                   8.327(2)
_cell_length_b                   11.225(3)
_cell_length_c                   16.443(5)
_cell_measurement_reflns_used    5018
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      1.91
_cell_volume                     1448.1(7)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2007)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2007)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2007)'
_computing_molecular_graphics    'Olex2 ver 1.1'
_computing_publication_material  'SHELX97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Saturn724+ CCD'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0402
_diffrn_reflns_av_sigmaI/netI    0.0577
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            25875
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         2.47
_exptl_absorpt_coefficient_mu    0.238
_exptl_absorpt_correction_T_max  0.9766
_exptl_absorpt_correction_T_min  0.9386
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrystalClear (Rigaku Inc., 2007)'
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.433
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             648
_exptl_crystal_size_max          0.27
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.293
_refine_diff_density_min         -0.208
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.07(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.107
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     797
_refine_ls_number_reflns         13083
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.107
_refine_ls_R_factor_all          0.0629
_refine_ls_R_factor_gt           0.0574
_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^)+(0.0370P)^2^+0.3318P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1133
_refine_ls_wR_factor_ref         0.1176
_reflns_number_gt                11971
_reflns_number_total             13083
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol202688h_si_002.cif
_cod_data_source_block           sa1443-a
_cod_original_cell_volume        1448.2(7)
_cod_original_sg_symbol_H-M      P1
_cod_database_code               1502593