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_4106338
_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            'C21 H23 F3 N2 O2'
_chemical_formula_weight         392.41
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 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                 100.954(14)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.440(10)
_cell_length_b                   12.594(10)
_cell_length_c                   12.697(10)
_cell_measurement_temperature    153(2)
_cell_volume                     1953(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      153(2)
_diffrn_measured_fraction_theta_full 0.895
_diffrn_measured_fraction_theta_max 0.895
_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  0.0563
_diffrn_reflns_av_sigmaI/netI    0.1984
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            16803
_diffrn_reflns_theta_full        28.09
_diffrn_reflns_theta_max         28.09
_diffrn_reflns_theta_min         1.62
_exptl_absorpt_coefficient_mu    0.105
_exptl_crystal_density_diffrn    1.334
_exptl_crystal_F_000             824
_refine_diff_density_max         0.218
_refine_diff_density_min         -0.143
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -1.4(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.705
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1017
_refine_ls_number_reflns         13747
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      0.705
_refine_ls_R_factor_all          0.1818
_refine_ls_R_factor_gt           0.0513
_refine_ls_shift/su_max          0.738
_refine_ls_shift/su_mean         0.015
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0269P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0878
_refine_ls_wR_factor_ref         0.1196
_reflns_number_gt                4266
_reflns_number_total             13747
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja202373d_si_002.cif
_cod_data_source_block           fang4m
_cod_database_code               4106338