Stereodivergency of triazolium and imidazolium-derived NHCs for catalytic, enantioselective cyclopentane synthesis.
Kaeobamrung, Juthanat; Bode, Jeffrey W.; Organic letters 11 (2009) 677–680; doi:10.1021/ol802739d

data_1503766
_publ_section_title
;
 Stereodivergency of triazolium and imidazolium-derived NHCs for
 catalytic, enantioselective cyclopentane synthesis.
;
_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              677
_journal_page_last               680
_journal_paper_doi               10.1021/ol802739d
_journal_volume                  11
_journal_year                    2009
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C18 H21 Br O5'
_chemical_formula_sum            'C18 H21 Br O5'
_chemical_formula_weight         397.26
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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
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_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.9519(7)
_cell_length_b                   9.6821(10)
_cell_length_c                   27.119(3)
_cell_measurement_temperature    143(1)
_cell_volume                     1825.4(3)
_computing_data_collection       'CrystalClear (Rigaku, 1999)'
_computing_data_reduction        'CrystalClear (Rigaku, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare, 1999)'
_diffrn_ambient_temperature      143(1)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device       'CCD Area Detector'
_diffrn_measurement_device_type  'Rigaku Mercury'
_diffrn_measurement_method       'phi and omega rotations'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0178
_diffrn_reflns_av_sigmaI/netI    0.0404
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            6821
_diffrn_reflns_theta_full        25.04
_diffrn_reflns_theta_max         25.04
_diffrn_reflns_theta_min         2.58
_exptl_absorpt_coefficient_mu    2.275
_exptl_absorpt_correction_T_max  0.672
_exptl_absorpt_correction_T_min  0.543
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;  Shape and scale corrections using equivalent reflections.
   Shape function based on spherical harmonics.
   Highest even and odd order for spherical harmonics:  4  and  3
   Laue group:  mmm
   Friedel opposites are equivalent.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.446
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.719
_refine_diff_density_min         -1.016
_refine_diff_density_rms         0.061
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.015(12)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.067
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     222
_refine_ls_number_reflns         3172
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.067
_refine_ls_R_factor_all          0.0456
_refine_ls_R_factor_gt           0.0390
_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^)+(0.0621P)^2^+0.3376P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1036
_refine_ls_wR_factor_ref         0.1088
_reflns_number_gt                2729
_reflns_number_total             3172
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol802739d_si_006.cif
_cod_data_source_block           shelxl
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_symetry_multiplicity' tag replaced with
'_atom_site_symmetry_multiplicity'.

Automatic conversion script
Id: cif_correct_tags 1440 2010-10-19 06:21:57Z saulius 

The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Multi-scan' changed to
'multi-scan' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_database_code               1503766