Nickel-catalyzed sequential 1,2-<i>N</i>-migration/BCBs ring-opening to access spirocyclobutyl β-amino acid esters.
Li, Xin-Yu; Xiao, Mei-Qiu; Zhou, Li-Juan; Zhang, Jia-Qi; Zhao, Meng-Yan; Wang, Shuo-Wen; Tang, Shi; Chemical communications (Cambridge, England) 61 (2025) 13473–13476; doi:10.1039/d5cc03029c

data_7134872
_publ_section_title
;
 Nickel-catalyzed sequential 1,2-<i>N</i>-migration/BCBs ring-opening to
 access spirocyclobutyl &#x3b2;-amino acid esters.
;
_journal_issue                   71
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              13473
_journal_page_last               13476
_journal_paper_doi               10.1039/d5cc03029c
_journal_volume                  61
_journal_year                    2025
_chemical_formula_moiety         'C31 H34 N2 O4'
_chemical_formula_sum            'C31 H34 N2 O4'
_chemical_formula_weight         498.60
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2025-01-09
_audit_creation_method
;
Olex2 1.5-beta
(compiled 2022.04.07 svn.rca3783a0 for OlexSys, GUI svn.r6439)
;
_audit_update_record
;
2025-01-11 deposited with the CCDC.	2025-07-28 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 96.5124(9)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.52568(11)
_cell_length_b                   20.80933(19)
_cell_length_c                   12.23495(12)
_cell_measurement_reflns_used    14465
_cell_measurement_temperature    99.99(10)
_cell_measurement_theta_max      72.5810
_cell_measurement_theta_min      3.6070
_cell_volume                     2662.56(5)
_computing_cell_refinement       'CrysAlisPro 1.171.43.121a (Rigaku OD, 2024)'
_computing_data_collection
'CrysAlisPro system (CCD 43.121a 64-bit (release 24-04-2024))'
_computing_data_reduction        'CrysAlisPro 1.171.43.121a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-beta (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXS  (Sheldrick, 2008)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      99.99(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            'HyPix-Arc 150'
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.976
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w     68.00  97.00   0.50    0.05    --   62.16  15.00 150.00   58
  2  \w     75.00 102.00   0.50    0.05    --   62.16  15.00 120.00   54
  3  \w     59.00  97.00   0.50    0.05    --   62.16  15.00 -90.00   76
  4  \w     71.00 100.00   0.50    0.05    --   62.16  15.00-120.00   58
  5  \w     66.00 102.00   0.50    0.05    --   62.16  15.00-180.00   72
  6  \w     68.00 111.00   0.50    0.05    --   74.38  15.00-150.00   86
  7  \w     58.00  83.00   0.50    0.05    --   62.16  15.00 -60.00   50
  8  \w     64.00 102.00   0.50    0.05    --   62.16  15.00 -30.00   76
  9  \w     65.00 104.00   0.50    0.05    --   71.22  15.00  30.00   78
 10  \w     67.00  92.00   0.50    0.05    --   74.38  15.00  30.00   50
 11  \w     67.00  92.00   0.50    0.05    --   74.38  15.00  60.00   50
 12  \w     80.00 107.00   0.50    0.05    --   74.38  15.00 150.00   54
 13  \w     55.00  90.00   0.50    0.05    --   62.16  15.00  30.00   70
 14  \w     77.00 114.00   0.50    0.05    --   74.38  15.00  90.00   74
 15  \w     71.00  99.00   0.50    0.05    --   74.38  15.00   0.00   56
 16  \w     71.00  97.00   0.50    0.05    --   74.38  15.00 -30.00   52
 17  \w     72.00  98.00   0.50    0.05    --   74.38  15.00-180.00   52
 18  \w     74.00 115.00   0.50    0.05    --   74.38  15.00 -90.00   82
 19  \w     29.00  76.00   0.50    0.05    --   62.16-125.00 -30.00   94
 20  \w     31.00  57.00   0.50    0.05    --   62.16-125.00  30.00   52
 21  \w     27.00  67.00   0.50    0.05    --   62.16-125.00  90.00   80
 22  \w     53.00  83.00   0.50    0.05    --   74.38-125.00 150.00   60
 23  \w     52.00  86.00   0.50    0.05    --   71.22-125.00 -30.00   68
 24  \w     26.00  55.00   0.50    0.05    --   62.16-125.00-150.00   58
 25  \w     45.00  76.00   0.50    0.05    --   62.16-125.00-180.00   62
 26  \w     47.00  72.00   0.50    0.05    --   74.38-125.00-180.00   50
 27  \w     42.00  67.00   0.50    0.05    --   74.38-125.00-150.00   50
 28  \w     38.00  79.00   0.50    0.05    --   74.38-125.00 -60.00   82
 29  \w     60.00  87.00   0.50    0.05    --   74.38-125.00  60.00   54
 30  \w     38.00  68.00   0.50    0.05    --   74.38-125.00 120.00   60
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'ROD, Synergy Custom system, HyPix-Arc 150'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0129961000
_diffrn_orient_matrix_UB_12      0.0212552000
_diffrn_orient_matrix_UB_13      -0.1214248000
_diffrn_orient_matrix_UB_21      -0.1080052000
_diffrn_orient_matrix_UB_22      -0.0494036000
_diffrn_orient_matrix_UB_23      -0.0275158000
_diffrn_orient_matrix_UB_31      -0.0995397000
_diffrn_orient_matrix_UB_32      0.0506145000
_diffrn_orient_matrix_UB_33      0.0245660000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0253
_diffrn_reflns_av_unetI/netI     0.0149
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.976
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            20526
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.976
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         72.856
_diffrn_reflns_theta_min         4.212
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.657
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.86478
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.121a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_density_diffrn    1.244
_exptl_crystal_description       block
_exptl_crystal_F_000             1064
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.651
_refine_diff_density_min         -0.279
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     337
_refine_ls_number_reflns         5174
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0470
_refine_ls_R_factor_gt           0.0448
_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^)+(0.0513P)^2^+1.4114P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1123
_refine_ls_wR_factor_ref         0.1138
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4860
_reflns_number_total             5174
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5cc03029c2.cif
_cod_data_source_block           091103
_cod_depositor_comments          'Adding full bibliography for 7134872.cif.'
_cod_original_cell_volume        2662.56(4)
_cod_database_code               7134872
_shelx_shelxl_version_number     2018/3
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C10(H10), C12(H12)
2.b Secondary CH2 refined with riding coordinates:
 C9(H9A,H9B), C11(H11A,H11B), C14(H14A,H14B), C15(H15A,H15B), C22(H22A,H22B)
2.c Aromatic/amide H refined with riding coordinates:
 C5(H5), C7(H7), C8(H8), C17(H17), C18(H18), C19(H19), C20(H20), C21(H21),
 C24(H24), C25(H25), C26(H26), C27(H27), C28(H28)
2.d Idealised Me refined as rotating group:
 C29(H29A,H29B,H29C), C30(H30A,H30B,H30C), C31(H31A,H31B,H31C)
;
_shelx_res_checksum              62437
_shelx_hkl_checksum              12346
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.411
_oxdiff_exptl_absorpt_empirical_full_min 0.702