Cu-catalyzed oxidative imino Diels-Alder cyclization: synthesis of dihydrofuroquinolines.
Kumar, Vikash; Dey, Ashutosh; Maurya, Rohit Kumar; Yadav, Abhay Kumar; Kumari, Megha; Singh, Angad Kumar; Khatravath, Mahender; Organic & biomolecular chemistry 24 (2026) 1659–1665; doi:10.1039/d5ob01758k

data_7160940
_publ_section_title
;
 Cu-catalyzed oxidative imino Diels-Alder cyclization: synthesis of
 dihydrofuroquinolines.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1659
_journal_page_last               1665
_journal_paper_doi               10.1039/d5ob01758k
_journal_volume                  24
_journal_year                    2026
_chemical_formula_moiety         'C17 H10 Br N O2'
_chemical_formula_sum            'C17 H10 Br N O2'
_chemical_formula_weight         340.17
_chemical_name_systematic        VK-428
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2025-12-30
_audit_creation_method
;
Olex2 1.5-ac5-024
(compiled 2022.04.12 svn.rca3783a0 for Rigaku Oxford Diffraction, GUI svn.r6498)
;
_cell_angle_alpha                79.6910(10)
_cell_angle_beta                 77.5300(10)
_cell_angle_gamma                71.1550(10)
_cell_formula_units_Z            2
_cell_length_a                   6.94070(10)
_cell_length_b                   10.10700(10)
_cell_length_c                   10.61130(10)
_cell_measurement_reflns_used    10835
_cell_measurement_temperature    293
_cell_measurement_theta_max      67.9900
_cell_measurement_theta_min      4.2860
_cell_volume                     683.037(14)
_computing_cell_refinement       'CrysAlisPro 1.171.44.105a (Rigaku OD, 2025)'
_computing_data_collection       'CrysAlisPro 1.171.44.105a (Rigaku OD, 2025)'
_computing_data_reduction        'CrysAlisPro 1.171.44.105a (Rigaku OD, 2025)'
_computing_molecular_graphics    'Olex2 1.5-ac5-024 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-ac5-024 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      293
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix3000
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.990
_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     14.00 110.00   0.50    0.20    --   40.83  77.00 150.00  192
  2  \w     14.00 110.00   0.50    0.20    --   40.83  77.00  90.00  192
  3  \w     14.00 110.00   0.50    0.20    --   40.83  77.00 -30.00  192
  4  \w     25.00 107.00   0.50    0.20    --   40.83  40.00 -66.00  164
  5  \w     25.00 107.00   0.50    0.20    --   40.83  40.00 -66.00  164
  6  \w    105.00 170.00   0.50    0.20    --   96.04  96.00 -60.00  130
  7  \w     99.00 160.00   0.50    0.20    --   96.04 117.00 -60.00  122
  8  \w     81.00 164.00   0.50    0.20    --   96.04 145.00-120.00  166
  9  \w     81.00 164.00   0.50    0.20    --   96.04 145.00-120.00  166
 10  \w     81.00 166.00   0.50    0.20    --   96.04  25.00   0.00  170
 11  \w     77.00 163.00   0.50    0.20    --   96.04  50.00  60.00  172
 12  \w     77.00 163.00   0.50    0.20    --   96.04  50.00  90.00  172
 13  \w     79.00 162.00   0.50    0.20    --   96.04  42.00 150.00  166
 14  \w     80.00 162.00   0.50    0.20    --   96.04  40.00 -66.00  164
 15  \w     77.00 163.00   0.50    0.20    --   96.04  50.00-120.00  172
 16  \w     77.00 163.00   0.50    0.20    --   96.04  50.00-150.00  172
 17  \w     77.00 163.00   0.50    0.20    --   96.04  50.00-180.00  172
 18  \w     82.00 164.00   0.50    0.20    --   96.04  33.00  30.00  164
 19  \w    -35.00  24.00   0.50    0.20    --   40.83 -11.00 150.00  118
 20  \w    -25.00  45.00   0.50    0.20    --   40.83 -40.00 139.00  140
 21  \w    -35.00  24.00   0.50    0.20    --   40.83 -11.00  60.00  118
 22  \w    -25.00  48.00   0.50    0.20    --   40.83 -43.00-120.00  146
 23  \w     18.00  78.00   0.50    0.20    --   40.83-104.00-150.00  120
 24  \w     41.00 100.00   0.50    0.20    --   40.83-138.00-150.00  118
 25  \w     41.00 100.00   0.50    0.20    --   40.83-138.00 -60.00  118
 26  \w     18.00  78.00   0.50    0.20    --   40.83-104.00 -30.00  120
 27  \w     44.00 127.00   0.50    0.20    --   96.04-145.00-150.00  166
 28  \w     32.00 110.00   0.50    0.20    --   96.04-117.00-150.00  156
 29  \w     44.00 127.00   0.50    0.20    --   96.04-145.00  30.00  166
 30  \w     32.00 110.00   0.50    0.20    --   96.04-117.00  30.00  156
 31  \w     23.00 106.00   0.50    0.20    --   96.04 -96.00  30.00  166
 32  \w     26.00 127.00   0.50    0.20    --   96.04 -87.00  90.00  202
 33  \w     26.00 127.00   0.50    0.20    --   96.04 -87.00-150.00  202
 34  \w     28.00  83.00   0.50    0.20    --   96.04 -68.00-120.00  110
 35  \w     28.00  68.00   0.50    0.20    --   96.04 -59.00-150.00   80
 36  \w     29.00  57.00   0.50    0.20    --   96.04 -50.00-120.00   56
 37  \w     29.00  57.00   0.50    0.20    --   96.04 -50.00-150.00   56
 38  \w     29.00  57.00   0.50    0.20    --   96.04 -50.00-180.00   56
 39  \w     29.00  57.00   0.50    0.20    --   96.04 -50.00 -90.00   56
 40  \w     28.00  83.00   0.50    0.20    --   96.04 -68.00  30.00  110
 41  \w     28.00  68.00   0.50    0.20    --   96.04 -59.00  60.00   80
 42  \w     29.00  57.00   0.50    0.20    --   96.04 -50.00  90.00   56
 43  \w    -28.00  31.00   0.50    0.20    --  -40.83  21.00  60.00  118
 44  \w    -37.00  27.00   0.50    0.20    --  -40.83  32.00-180.00  128
 45  \w    -37.00  27.00   0.50    0.20    --  -40.83  32.00-180.00  128
 46  \w    -45.00  25.00   0.50    0.20    --  -40.83  40.00 -66.00  140
 47  \w    -48.00  26.00   0.50    0.20    --  -40.83  43.00 120.00  148
 48  \w    -48.00  26.00   0.50    0.20    --  -40.83  43.00 120.00  148
 49  \w    -45.00 -16.00   0.50    0.20    --  -82.50  40.00 -66.00   58
 50  \w    -47.00 -15.00   0.50    0.20    --  -82.50  42.00-120.00   64
 51  \w    -47.00 -15.00   0.50    0.20    --  -82.50  42.00  30.00   64
 52  \w    -47.00 -15.00   0.50    0.20    --  -82.50  42.00  60.00   64
 53  \w    -47.00 -15.00   0.50    0.20    --  -82.50  42.00  90.00   64
 54  \w    -47.00 -15.00   0.50    0.20    --  -82.50  42.00 150.00   64
 55  \w   -150.00 -69.00   0.50    0.20    --  -82.50 -33.00  60.00  162
 56  \w   -150.00 -58.00   0.50    0.20    --  -82.50 -68.00 -90.00  184
 57  \w   -151.00 -55.00   0.50    0.20    --  -82.50 -77.00 -30.00  192
 58  \w   -151.00 -55.00   0.50    0.20    --  -82.50 -77.00  30.00  192
 59  \w   -151.00 -55.00   0.50    0.20    --  -82.50 -77.00 120.00  192
 60  \w   -148.00 -66.00   0.50    0.20    --  -82.50 -40.00 139.00  164
 61  \w   -148.00 -66.00   0.50    0.20    --  -82.50 -40.00 139.00  164
 62  \w   -107.00 -25.00   0.50    0.20    --  -40.83 -40.00 139.00  164
 63  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00   0.00  190
 64  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00-150.00  190
 65  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00-180.00  190
 66  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00-120.00  190
 67  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00 -90.00  190
 68  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00 -60.00  190
 69  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00 -30.00  190
 70  \w   -109.00 -14.00   0.50    0.20    --  -40.83 -77.00 120.00  190
 71  \w   -108.00 -17.00   0.50    0.20    --  -40.83 -65.00  90.00  182
 72  \w   -108.00 -17.00   0.50    0.20    --  -40.83 -65.00  30.00  182
 73  \w   -107.00 -25.00   0.50    0.20    --  -40.83 -40.00 139.00  164
 74  \w    -84.00 -18.00   0.50    0.20    --  -82.50 117.00   0.00  132
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy, Dualflex, HyPix3000'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.1735530000
_diffrn_orient_matrix_UB_12      0.0681086000
_diffrn_orient_matrix_UB_13      -0.0591422000
_diffrn_orient_matrix_UB_21      0.1408195000
_diffrn_orient_matrix_UB_22      -0.1414802000
_diffrn_orient_matrix_UB_23      -0.0454762000
_diffrn_orient_matrix_UB_31      -0.0817745000
_diffrn_orient_matrix_UB_32      0.0406408000
_diffrn_orient_matrix_UB_33      -0.1298299000
_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  0.0286
_diffrn_reflns_av_unetI/netI     0.0164
_diffrn_reflns_Laue_measured_fraction_full 0.995
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            13242
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         68.080
_diffrn_reflns_theta_min         4.297
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'PhotonJet (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    4.133
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.44076
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.44.105a (Rigaku Oxford Diffraction, 2025)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light white'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    white
_exptl_crystal_density_diffrn    1.654
_exptl_crystal_description       block
_exptl_crystal_F_000             340
_exptl_crystal_preparation
'Saturated solution of sample prepared in DCM solvent then directly diffused by diethyl ether solvent'
_exptl_crystal_recrystallization_method
'Saturated solution on diffusion with diethyl ether for 10 days gives white to colorless block like single crystal'
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.395
_refine_diff_density_min         -0.555
_refine_diff_density_rms         0.049
_refine_ls_extinction_coef       0.0097(6)
_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   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     191
_refine_ls_number_reflns         2474
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.0307
_refine_ls_R_factor_gt           0.0294
_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^)+(0.0412P)^2^+0.3492P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0767
_refine_ls_wR_factor_ref         0.0779
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2338
_reflns_number_total             2474
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob01758k2.cif
_cod_data_source_block           vk-428_auto
_cod_depositor_comments          'Adding full bibliography for 7160940.cif.'
_cod_original_cell_volume        683.038(14)
_cod_database_code               7160940
_shelx_shelxl_version_number     2019/3
_chemical_oxdiff_formula         'C H N O'
_shelx_estimated_absorpt_t_max   0.576
_shelx_estimated_absorpt_t_min   0.413
_diffrn_oxdiff_digest_od_ed
;

;
_olex2_refinement_description
;
1.a Secondary CH2 refined with riding coordinates:
 C1(H1A,H1B)
1.b Aromatic/amide H refined with riding coordinates:
 C7(H7), C5(H5), C6(H6), C17(H17), C13(H13), C16(H16), C14(H14), C15(H15)
;
_shelx_res_checksum              55392
_shelx_hkl_checksum              58891
_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 2.039
_oxdiff_exptl_absorpt_empirical_full_min 0.672