N-Heterocyclic carbene-catalyzed [4 + 2] cyclization of α,β-unsaturated carboxylic acids bearing γ-H with isatins: an enantioselective synthesis of spirocyclic oxindole-dihydropyranones.
Zhu, Ling; Yu, Chenxia; Li, Tuanjie; Wang, Yuhong; Lu, Yinan; Wang, Wenjing; Yao, Changsheng; Organic & biomolecular chemistry 14 (2016) 1485–1491; doi:10.1039/c5ob02160j

data_7154855
_publ_section_title
;
 N-Heterocyclic carbene-catalyzed [4 + 2] cyclization of \a,\b-unsaturated
 carboxylic acids bearing \g-H with isatins: an enantioselective synthesis
 of spirocyclic oxindole-dihydropyranones.
;
_journal_issue                   4
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1485
_journal_page_last               1491
_journal_paper_doi               10.1039/c5ob02160j
_journal_volume                  14
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H16 Br N O4'
_chemical_formula_sum            'C20 H16 Br N O4'
_chemical_formula_weight         414.25
_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
_audit_update_record
;
2015-02-03 deposited with the CCDC.
2015-12-16 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.7918(15)
_cell_length_b                   10.8744(17)
_cell_length_c                   17.136(3)
_cell_measurement_reflns_used    6123
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      24.88
_cell_measurement_theta_min      2.22
_cell_volume                     1824.6(5)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0250
_diffrn_reflns_av_sigmaI/netI    0.0385
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            13399
_diffrn_reflns_theta_full        25.56
_diffrn_reflns_theta_max         25.56
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    2.278
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.508
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.390
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.007(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.053
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     237
_refine_ls_number_reflns         3383
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.0347
_refine_ls_R_factor_gt           0.0284
_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^)+(0.0423P)^2^+0.0026P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0742
_refine_ls_wR_factor_ref         0.0770
_reflns_number_gt                2992
_reflns_number_total             3383
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5ob02160j2.cif
_cod_data_source_block           1125
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/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 4268 2015-11-12 08:31:59Z antanas 

 Adding full bibliography for 7154855.cif.
;
_cod_original_sg_symbol_H-M      'P2(1)2(1)2(1) '
_cod_database_code               7154855