N-Heterocyclic carbene-catalyzed enantioselective synthesis of functionalized cyclopentenes via alpha,beta-unsaturated acyl azoliums
Santigopal Mondal; Santhivardhana Reddy Yetra; Atanu Patra; Sunita S. Kunte; Rajesh G. Gonnade; Akkattu T. Biju; Chem.Commun. 50 (2014) 14539–; doi:10.1039/C4cc07433E

data_7115971
_publ_section_title
;
 N-Heterocyclic carbene-catalyzed enantioselective synthesis of
 functionalized cyclopentenes via alpha,beta-unsaturated acyl azoliums
;
_journal_name_full               Chem.Commun.
_journal_page_first              14539
_journal_paper_doi               10.1039/C4cc07433E
_journal_volume                  50
_journal_year                    2014
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C21 H19 Br O4'
_chemical_formula_sum            'C21 H19 Br O4'
_chemical_formula_weight         415.27
_space_group_IT_number           145
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_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                120.00
_cell_formula_units_Z            3
_cell_length_a                   11.7082(7)
_cell_length_b                   11.7082(7)
_cell_length_c                   11.9217(8)
_cell_measurement_reflns_used    9912
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      24.47
_cell_measurement_theta_min      2.64
_cell_volume                     1415.30(15)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w 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  0.0360
_diffrn_reflns_av_sigmaI/netI    0.0519
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            32442
_diffrn_reflns_theta_full        33.61
_diffrn_reflns_theta_max         33.61
_diffrn_reflns_theta_min         2.01
_exptl_absorpt_coefficient_mu    2.201
_exptl_absorpt_correction_T_max  0.4656
_exptl_absorpt_correction_T_min  0.4118
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SADABS'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.462
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             636
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: dichloromethane'
_exptl_crystal_size_max          0.49
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.41
_refine_diff_density_max         0.442
_refine_diff_density_min         -0.431
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.011(5)
_refine_ls_extinction_coef       0.0174(11)
_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   0.995
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     238
_refine_ls_number_reflns         7324
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.995
_refine_ls_R_factor_all          0.0759
_refine_ls_R_factor_gt           0.0340
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0294P)^2^+0.0586P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0730
_refine_ls_wR_factor_ref         0.0838
_reflns_number_gt                4525
_reflns_number_total             7324
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c4cc07433e2.cif
_cod_data_source_block           sgm_sc_76_0m
_cod_original_sg_symbol_H-M      P3(2)
_cod_database_code               7115971