Reversible Twisting of Primary Amides via Ground State N-C(O) Destabilization: Highly Twisted Rotationally-Inverted Acyclic Amides.
Meng, Guangrong; Shi, Shicheng; Lalancette, Roger A.; Szostak, Roman; Szostak, Michal; Journal of the American Chemical Society  (2017) –; doi:10.1021/jacs.7b11309

data_4126994
_publ_section_title
;
 Reversible Twisting of Primary Amides via Ground State N-C(O)
 Destabilization: Highly Twisted Rotationally-Inverted Acyclic Amides.
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_paper_doi               10.1021/jacs.7b11309
_journal_year                    2017
_chemical_formula_moiety         'C17 H23 N O5'
_chemical_formula_sum            'C17 H23 N O5'
_chemical_formula_weight         321.36
_space_group_crystal_system      orthorhombic
_space_group_IT_number           61
_space_group_name_Hall           '-P 2ac 2ab'
_space_group_name_H-M_alt        'P b c a'
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   16.7598(3)
_cell_length_b                   16.5657(3)
_cell_length_c                   12.5706(2)
_cell_measurement_reflns_used    9847
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      68.74
_cell_measurement_theta_min      4.42
_cell_volume                     3490.07(10)
_computing_cell_refinement       'APEX 2'
_computing_data_collection       'APEX 2 (Bruker, 2006)'
_computing_data_reduction        'SAINT (Bruker, 2005)'
_computing_molecular_graphics    SHELXTL
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.973
_diffrn_measurement_device_type  'Bruker SMART CCD Apex-II area-detector'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0364
_diffrn_reflns_av_unetI/netI     0.0161
_diffrn_reflns_Laue_measured_fraction_full 0.991
_diffrn_reflns_Laue_measured_fraction_max 0.973
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            30555
_diffrn_reflns_point_group_measured_fraction_full 0.991
_diffrn_reflns_point_group_measured_fraction_max 0.973
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.965
_diffrn_reflns_theta_min         5.145
_exptl_absorpt_coefficient_mu    0.742
_exptl_absorpt_correction_T_max  0.947
_exptl_absorpt_correction_T_min  0.835
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2008a)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.223
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1376
_exptl_crystal_size_max          0.379
_exptl_crystal_size_mid          0.209
_exptl_crystal_size_min          0.149
_refine_diff_density_max         0.457
_refine_diff_density_min         -0.215
_refine_diff_density_rms         0.038
_refine_ls_extinction_coef       0.00037(7)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.083
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     215
_refine_ls_number_reflns         3151
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.083
_refine_ls_R_factor_all          0.0400
_refine_ls_R_factor_gt           0.0373
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0406P)^2^+1.8696P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0936
_refine_ls_wR_factor_ref         0.0956
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2933
_reflns_number_total             3151
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b11309_si_004.cif
_cod_data_source_block           P212121_a
_cod_database_code               4126994
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.766
_shelx_estimated_absorpt_t_max   0.897
_shelx_res_checksum              48004
_shelx_hkl_checksum              96702