Synthesis of polysubstituted cyclobutanes through a photoredox strain-release/[3,3]-rearrangement cascade
Zhang, Fangqing; Xu, Chun; Zhang, Zichun; Yang, Zhuang; Peng, Tao; Shao, Wen; Feng, Xiaoming; Liu, Yangbin; Chemical Science 16 (2025) 11508–11518; doi:10.1039/D5SC01431J

data_1574746
_publ_section_title
;
 Synthesis of polysubstituted cyclobutanes through a photoredox
 strain-release/[3,3]-rearrangement cascade
;
_journal_issue                   25
_journal_name_full               'Chemical Science'
_journal_page_first              11508
_journal_page_last               11518
_journal_paper_doi               10.1039/D5SC01431J
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety         'C19 H24 N2 O2'
_chemical_formula_sum            'C19 H24 N2 O2'
_chemical_formula_weight         312.40
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_audit_creation_date             2024-07-12
_audit_creation_method
;
Olex2 1.5
(compiled 2024.02.16 svn.r378c4104 for OlexSys, GUI svn.r6928)
;
_audit_update_record
;
2024-11-19 deposited with the CCDC.	2025-05-28 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 108.624(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.7265(2)
_cell_length_b                   14.7461(2)
_cell_length_c                   12.5014(2)
_cell_measurement_reflns_used    8141
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      76.6770
_cell_measurement_theta_min      4.7720
_cell_volume                     1699.16(5)
_computing_cell_refinement       'CrysAlisPro 1.171.43.129a (Rigaku OD, 2024)'
_computing_data_collection       'CrysAlisPro 1.171.43.129a (Rigaku OD, 2024)'
_computing_data_reduction        'CrysAlisPro 1.171.43.129a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'olex2.solve 1.5 (Bourhis et al., 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.00(10)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.942
_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     74.00 100.00   0.50    0.11    --  105.65 -94.00  90.00   52
  2  \w     36.00  62.00   0.50    0.11    --  105.65 -94.00  90.00   52
  3  \w    -21.00  28.00   0.50    0.05    --   46.79 -94.00-108.00   98
  4  \w     31.00  57.00   0.50    0.05    --   46.79 -94.00-108.00   52
  5  \w     33.00 104.00   0.50    0.11    --  105.65 -94.00-108.00  142
  6  \w     33.00  58.00   0.50    0.11    --  105.65 -61.00 -90.00   50
  7  \w     33.00  58.00   0.50    0.11    --  105.65 -61.00 -60.00   50
  8  \w    -27.00  -1.00   0.50    0.05    --   46.79 -19.00-180.00   52
  9  \w    -15.00  28.00   0.50    0.05    --   46.79 -19.00-120.00   86
 10  \w    118.00 144.00   0.50    0.11    --  105.65  94.00   3.00   52
 11  \w    131.00 157.00   0.50    0.11    --  105.65  61.00 -30.00   52
 12  \w    100.00 126.00   0.50    0.11    --  105.65  61.00 -30.00   52
 13  \w    -64.00 -33.00   0.50    0.11    -- -104.00  61.00-180.00   62
 14  \w    -57.00 -31.00   0.50    0.11    -- -104.00  61.00-150.00   52
 15  \w    -68.00 -36.00   0.50    0.11    -- -104.00  61.00 -30.00   64
 16  \w    -68.00 -34.00   0.50    0.11    -- -104.00  61.00 120.00   68
 17  \w    -65.00 -34.00   0.50    0.11    -- -104.00  61.00 150.00   62
 18  \w    -38.00  26.00   0.50    0.05    --  -46.79  37.00 120.00  128
 19  \w    -62.00  25.00   0.50    0.05    --  -46.79  94.00   3.00  174
 20  \w   -101.00 -37.00   0.50    0.11    -- -104.00  94.00   3.00  128
 21  \w   -174.00 -96.00   0.50    0.11    -- -104.00 -45.00 -90.00  156
 22  \w   -149.00-116.00   0.50    0.11    -- -104.00 -94.00-108.00   66
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.1352807000
_diffrn_orient_matrix_UB_12      0.0585990000
_diffrn_orient_matrix_UB_13      0.0549517000
_diffrn_orient_matrix_UB_21      0.0658712000
_diffrn_orient_matrix_UB_22      -0.0770490000
_diffrn_orient_matrix_UB_23      0.0839784000
_diffrn_orient_matrix_UB_31      0.0727664000
_diffrn_orient_matrix_UB_32      -0.0392616000
_diffrn_orient_matrix_UB_33      -0.0827351000
_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  0.0212
_diffrn_reflns_av_unetI/netI     0.0206
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.942
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            10262
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.942
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.910
_diffrn_reflns_theta_min         4.788
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.630
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.98301
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.129a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.221
_exptl_crystal_description       cube
_exptl_crystal_F_000             672
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.208
_refine_diff_density_min         -0.230
_refine_diff_density_rms         0.035
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     233
_refine_ls_number_reflns         3388
_refine_ls_number_restraints     52
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.0408
_refine_ls_R_factor_gt           0.0376
_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^)+(0.0466P)^2^+0.5207P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0956
_refine_ls_wR_factor_ref         0.0979
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3100
_reflns_number_total             3388
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc01431j2.cif
_cod_data_source_block           zfq-2-20240708_auto
_cod_depositor_comments
'Adding full bibliography for 1574745--1574746.cif.'
_cod_database_code               1574746
_shelx_shelxl_version_number     2014/7
_chemical_oxdiff_formula         'C H O N'
_shelx_estimated_absorpt_t_max   0.884
_shelx_estimated_absorpt_t_min   0.884
_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, All O(H) groups
2. Rigid bond restraints
 C19, C20
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.002
3. Uiso/Uaniso restraints and constraints
C19 \\sim C22 \\sim C23 \\sim C22A \\sim C23A: within 2A with sigma of 0.01 and
sigma for terminal atoms of 0.02 within 2A
4. Same fragment restrains
{C19, C22A, C23A} sigma for 1-2: 0.01, 1-3: 0.02
as in
{C19, C22, C23}
5. Others
 Sof(C22A)=Sof(H22C)=Sof(H22D)=Sof(C23A)=Sof(H23A)=1-FVAR(1)
 Sof(C22)=Sof(H22A)=Sof(H22B)=Sof(C23)=Sof(H23)=FVAR(1)
 Sof(H18)=1-FVAR(2)
 Sof(H17)=FVAR(2)
6.a Ternary CH refined with riding coordinates:
 C12(H12)
6.b Secondary CH2 refined with riding coordinates:
 C9(H9A,H9B), C14(H14A,H14B), C15(H15A,H15B)
6.c Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C5(H5), C6(H6), C23(H23), C23A(H23A)
6.d X=CH2 refined with riding coordinates:
 C22(H22A,H22B), C22A(H22C,H22D)
6.e Idealised Me refined as rotating group:
 C8(H8A,H8B,H8C), C20(H20A,H20B,H20C), C21(H21A,H21B,H21C)
6.f Idealised tetrahedral OH refined as rotating group:
 O17(H17), O18(H18)
;
_shelx_res_checksum              52679
_shelx_hkl_checksum              6887
_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 1.071
_oxdiff_exptl_absorpt_empirical_full_min 0.922