Cooperative N-heterocyclic carbene (NHC)-Lewis acid-mediated regioselective umpolung formal [3 + 2] annulations of alkynyl aldehydes with isatins.
Zhang, Yu; Lu, Yingyan; Tang, Weifang; Lu, Tao; Du, Ding; Organic & biomolecular chemistry 12 (2014) 3009–3015; doi:10.1039/c4ob00145a

data_7153755
_publ_section_title
;
 Cooperative N-heterocyclic carbene (NHC)-Lewis acid-mediated
 regioselective umpolung formal [3 + 2] annulations of alkynyl aldehydes
 with isatins.
;
_journal_issue                   19
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3009
_journal_page_last               3015
_journal_paper_doi               10.1039/c4ob00145a
_journal_volume                  12
_journal_year                    2014
_chemical_absolute_configuration unk
_chemical_formula_sum            'C18 H13 N O3'
_chemical_formula_weight         291.29
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.9540(18)
_cell_length_b                   9.4550(19)
_cell_length_c                   17.176(3)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13
_cell_measurement_theta_min      10
_cell_volume                     1454.1(5)
_computing_cell_refinement       'CAD4 EXPRESS'
_computing_data_collection       'CAD4 EXPRESS(Enraf-Nonius,1994)'
_computing_data_reduction        'XCAD4(Harms & Wocadlo,1995)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Nonius cad4'
_diffrn_measurement_method       \w/2\q
_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  0.0315
_diffrn_reflns_av_sigmaI/netI    0.0530
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            3006
_diffrn_reflns_theta_full        25.38
_diffrn_reflns_theta_max         25.38
_diffrn_reflns_theta_min         2.37
_diffrn_standards_decay_%        1
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  2h
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.9909
_exptl_absorpt_correction_T_min  0.9731
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    1.331
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             608
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.135
_refine_diff_density_min         -0.177
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.4(19)
_refine_ls_extinction_coef       0.102(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.009
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     200
_refine_ls_number_reflns         2668
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.009
_refine_ls_R_factor_all          0.0713
_refine_ls_R_factor_gt           0.0474
_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^)+(0.0700P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1126
_refine_ls_wR_factor_ref         0.1259
_reflns_number_gt                2015
_reflns_number_total             2668
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c4ob00145a2.cif
_cod_data_source_block           x
_cod_depositor_comments
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The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/current/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7153755