Squaramide-catalyzed aza-Michael/Michael cyclization cascade reaction: one-pot enantioselective construction of highly functionalized γ-lactams.
Wu, Sheng-Feng; Wang, Zhi-Yuan; Sun, Xing-Wen; Organic & biomolecular chemistry 23 (2025) 5373–5379; doi:10.1039/d5ob00572h

data_7160546
_publ_section_title
;
 Squaramide-catalyzed aza-Michael/Michael cyclization cascade reaction:
 one-pot enantioselective construction of highly functionalized
 &#x3b3;-lactams.
;
_journal_issue                   22
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5373
_journal_page_last               5379
_journal_paper_doi               10.1039/d5ob00572h
_journal_volume                  23
_journal_year                    2025
_chemical_absolute_configuration rmad
_chemical_formula_sum            'C26 H24 N2 O5'
_chemical_formula_weight         444.47
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2019/2
_audit_update_record
;
2024-04-22 deposited with the CCDC.	2025-04-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            12
_cell_length_a                   11.970(2)
_cell_length_b                   20.271(4)
_cell_length_c                   27.852(5)
_cell_measurement_reflns_used    9236
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      56.91
_cell_measurement_theta_min      3.35
_cell_volume                     6758(2)
_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-2019/2 (Sheldrick, 2019)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           GaK\a
_diffrn_radiation_wavelength     1.34139
_diffrn_reflns_av_R_equivalents  0.0509
_diffrn_reflns_av_unetI/netI     0.0494
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.994
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            40465
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        53.594
_diffrn_reflns_theta_max         57.190
_diffrn_reflns_theta_min         3.350
_exptl_absorpt_coefficient_mu    0.477
_exptl_absorpt_correction_T_max  0.864
_exptl_absorpt_correction_T_min  0.622
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.310
_exptl_crystal_description       block
_exptl_crystal_F_000             2808
_exptl_crystal_size_max          0.120
_exptl_crystal_size_mid          0.090
_exptl_crystal_size_min          0.070
_refine_diff_density_max         0.277
_refine_diff_density_min         -0.256
_refine_diff_density_rms         0.061
_refine_ls_abs_structure_details
; 
 Flack x determined using 3735 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   -0.02(8)
_refine_ls_extinction_coef       0.0017(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2019/2 (Sheldrick 2019)'
_refine_ls_goodness_of_fit_ref   1.083
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     896
_refine_ls_number_reflns         13816
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.083
_refine_ls_R_factor_all          0.0985
_refine_ls_R_factor_gt           0.0577
_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^)+(0.0943P)^2^+2.2663P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1452
_refine_ls_wR_factor_ref         0.1860
_reflns_Friedel_coverage         0.819
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.991
_reflns_number_gt                9844
_reflns_number_total             13816
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob00572h2.cif
_cod_data_source_block           ga_230919e_a
_cod_depositor_comments          'Adding full bibliography for 7160546.cif.'
_cod_database_code               7160546
_shelx_shelxl_version_number     2019/2
_shelx_estimated_absorpt_t_min   0.945
_shelx_estimated_absorpt_t_max   0.967
_shelx_res_checksum              85255