Conformational Study of 9-Dehydro-9-Trifluoromethyl Cinchona Alkaloids via 19F NMR Spectroscopy: Emergence of Trifluoromethyl Moiety as a Conformational Stabilizer and a Probe
G. K. Surya Prakash; Fang Wang; Chuanfa Ni; Jingguo Shen; Ralf Haiges; Andrei K. Yudin; Thomas Mathew; George A. Olah; Journal of the American Chemical Society 133 (2011) 9992–9995; doi:10.1021/ja202373d

data_4106339
_publ_section_title
;
 Conformational Study of 9-Dehydro-9-Trifluoromethyl Cinchona Alkaloids
 via 19F NMR Spectroscopy: Emergence of Trifluoromethyl Moiety as a
 Conformational Stabilizer and a Probe
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9992
_journal_page_last               9995
_journal_paper_doi               10.1021/ja202373d
_journal_volume                  133
_journal_year                    2011
_chemical_formula_sum            'C20 H22 N2 O2'
_chemical_formula_weight         322.40
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 95.021(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.293(2)
_cell_length_b                   8.115(2)
_cell_length_c                   12.531(3)
_cell_measurement_reflns_used    2126
_cell_measurement_temperature    143(2)
_cell_measurement_theta_max      25.97
_cell_measurement_theta_min      2.47
_cell_volume                     840.1(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      143(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_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  0.0408
_diffrn_reflns_av_sigmaI/netI    0.0771
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            7135
_diffrn_reflns_theta_full        27.44
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         2.47
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.274
_exptl_crystal_density_meas      0
_exptl_crystal_description       plate
_exptl_crystal_F_000             344
_refine_diff_density_max         0.322
_refine_diff_density_min         -0.214
_refine_diff_density_rms         0.052
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -1(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         3621
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.021
_refine_ls_R_factor_all          0.1113
_refine_ls_R_factor_gt           0.0638
_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^)+(0.0674P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1257
_refine_ls_wR_factor_ref         0.1470
_reflns_number_gt                2325
_reflns_number_total             3621
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja202373d_si_003.cif
_cod_data_source_block           fang1m
_cod_database_code               4106339