N-heterocyclic carbene-catalyzed [4 + 2] cycloaddition of ketenes and 3-aroylcoumarins: highly enantioselective synthesis of dihydrocoumarin-fused dihydropyranones.
Jian, Teng-Yue; Chen, Xiang-Yu; Sun, Li-Hui; Ye, Song; Organic & biomolecular chemistry 11 (2013) 158–163; doi:10.1039/c2ob26804c

data_7152773
_publ_section_title
;
 N-heterocyclic carbene-catalyzed [4 + 2] cycloaddition of ketenes and
 3-aroylcoumarins: highly enantioselective synthesis of
 dihydrocoumarin-fused dihydropyranones.
;
_journal_issue                   1
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              158
_journal_page_last               163
_journal_paper_doi               10.1039/c2ob26804c
_journal_volume                  11
_journal_year                    2013
_chemical_formula_moiety         'C26 H19 Cl O4'
_chemical_formula_sum            'C26 H19 Cl O4'
_chemical_formula_weight         430.86
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 119.437(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.196(5)
_cell_length_b                   13.001(4)
_cell_length_c                   13.423(5)
_cell_measurement_reflns_used    6424
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      32.8090
_cell_measurement_theta_min      1.5664
_cell_volume                     2005.6(12)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2008)'
_computing_molecular_graphics
;
Mercury: visualization and analysis of crystal structures, C. F. Macrae,
P. R. Edgington, P. McCabe, E. Pidcock, G. P. Shields, R. Taylor,
M. Towler and J. van de Streek, J. Appl. Cryst., 39, 453-457, 2006.
;
_computing_publication_material  'SHELX-97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELX-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELX-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'MM007HF + CCD (Saturn724+)'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_diffrn_radiation_monochromator  Confocal
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0952
_diffrn_reflns_av_sigmaI/netI    0.1058
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            14061
_diffrn_reflns_theta_full        27.46
_diffrn_reflns_theta_max         27.46
_diffrn_reflns_theta_min         1.77
_exptl_absorpt_coefficient_mu    0.223
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6700
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrystalClear (Rigaku Inc., 2008)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.427
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             896
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.261
_refine_diff_density_min         -0.270
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.171
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     281
_refine_ls_number_reflns         4568
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.171
_refine_ls_R_factor_all          0.1441
_refine_ls_R_factor_gt           0.0935
_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^)+(0.0375P)^2^+1.3913P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1489
_refine_ls_wR_factor_ref         0.1657
_reflns_number_gt                3097
_reflns_number_total             4568
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26804c.txt
_cod_data_source_block           a
_cod_original_cell_volume        2005.7(11)
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7152773