A new mode of cyclobutenedione ring opening for the synthesis of 2-oxobut-3-enamides and tetrasubstituted furans.
Bennett, Ryan M.; Sun, Wei; Wilson, Dharyl C.; Light, Mark E.; Harrowven, David C.; Chemical communications (Cambridge, England) 57 (2021) 5694–5697; doi:10.1039/d1cc02097h

data_7128287
_publ_section_title
;
 A new mode of cyclobutenedione ring opening for the synthesis of
 2-oxobut-3-enamides and tetrasubstituted furans.
;
_journal_issue                   46
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              5694
_journal_page_last               5697
_journal_paper_doi               10.1039/d1cc02097h
_journal_volume                  57
_journal_year                    2021
_chemical_formula_moiety         'C18 H18 N2 O2'
_chemical_formula_sum            'C18 H18 N2 O2'
_chemical_formula_weight         294.34
_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   mixed
_atom_sites_solution_primary     dual
_audit_creation_date             2016-08-19
_audit_creation_method
;
Olex2 1.2-alpha
(compiled 2016.08.15 svn.r3327 for OlexSys, GUI svn.r5212)
;
_audit_update_record
;
2016-08-19 deposited with the CCDC.	2021-05-05 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 98.5880(10)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   22.0147(2)
_cell_length_b                   4.41720(10)
_cell_length_c                   31.4419(4)
_cell_measurement_reflns_used    22867
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      69.9830
_cell_measurement_theta_min      2.0100
_cell_volume                     3023.23(8)
_computing_cell_refinement
;
'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
;
_computing_data_collection       'CrystalClear-SM Expert 3.1 b27 (Rigaku, 2013)'
_computing_data_reduction
;
'CrysAlisPro 1.171.38.41 (Rigaku OD, 2015)'
;
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'CCD area detector'
_diffrn_detector_area_resol_mean 22.2222
_diffrn_detector_type            'Rigaku HG Saturn944+ (2x2 bin mode)'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.995
_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   -103.00  77.00   1.00   10.00    --  -13.00  60.00-120.00  180
  2  \w      6.00  49.00   1.00   10.00    --  -13.00  45.00  60.00   43
  3  \w     -5.00  48.00   1.00   10.00    --  -13.00  37.00  30.00   53
  4  \w     21.00  41.00   1.00   10.00    --  -13.00  37.00 -90.00   20
  5  \w     26.00  46.00   1.00   10.00    --  -13.00  45.00  90.00   20
  6  \w     51.00  71.00   1.00   10.00    --  -13.00  45.00-180.00   20
  7  \w   -179.00   0.00   1.00   40.00    --  -90.00  37.00 -30.00  179
  8  \w   -149.00   0.00   1.00   40.00    --  -90.00  60.00  60.00  149
  9  \w   -162.00   0.00   1.00   40.00    --  -90.00  60.00  30.00  162
 10  \w   -153.00   0.00   1.00   40.00    --  -90.00  60.00  90.00  153
 11  \w   -169.00 -95.00   1.00   40.00    --  -90.00  60.00 -90.00   74
 12  \w   -153.00   0.00   1.00   40.00    --  -90.00  60.00 -30.00  153
 13  \w   -126.00   0.00   1.00   40.00    --  -90.00  60.00   0.00  126
 14  \w   -124.00   0.00   1.00   40.00    --  -90.00   0.00 -30.00  124
 15  \w   -162.00   0.00   1.00   40.00    --  -90.00  52.00 -30.00  162
 16  \w   -104.00   0.00   1.00   40.00    --  -90.00  52.00   0.00  104
 17  \w   -107.00   0.00   1.00   40.00    --  -90.00  45.00  30.00  107
 18  \w    -49.00   0.00   1.00   40.00    --  -90.00  52.00  60.00   49
 19  \w   -112.00   0.00   1.00   40.00    --  -90.00  52.00  90.00  112
 20  \w   -128.00 -69.00   1.00   40.00    --  -90.00  52.00 -90.00   59
 21  \w    -20.00   0.00   1.00   40.00    --  -90.00  52.00  30.00   20
 22  \w   -163.00 -28.00   1.00   40.00    --  -90.00  15.00 120.00  135
 23  \w    -38.00  -2.00   1.00   40.00    --  -90.00  45.00   0.00   36
 24  \w    -20.00   0.00   1.00   40.00    --  -90.00  45.00  60.00   20
 25  \w    -20.00   0.00   1.00   40.00    --  -90.00  45.00 -30.00   20
 26  \w    -20.00   0.00   1.00   40.00    --  -90.00  45.00  90.00   20
 27  \w   -102.00 -78.00   1.00   40.00    --  -90.00  52.00 -60.00   24
 28  \w    -84.00 -18.00   1.00   40.00    --  -90.00  30.00  90.00   66
 29  \w    -20.00   0.00   1.00   40.00    --  -90.00  37.00  60.00   20
 30  \w    -20.00   0.00   1.00   40.00    --  -90.00  60.00 -60.00   20
;
_diffrn_measurement_device       'three-circle quarter \c goniometer'
_diffrn_measurement_device_type  'Rigaku AFC11 007-HF'
_diffrn_measurement_method       'profile data from \w-scans'
_diffrn_measurement_specimen_support 'MiTeGen MicroMesh'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0522206000
_diffrn_orient_matrix_UB_12      -0.0705648000
_diffrn_orient_matrix_UB_13      0.0370059000
_diffrn_orient_matrix_UB_21      0.0446801000
_diffrn_orient_matrix_UB_22      -0.0454943000
_diffrn_orient_matrix_UB_23      -0.0327780000
_diffrn_orient_matrix_UB_31      0.0169069000
_diffrn_orient_matrix_UB_32      0.3385436000
_diffrn_orient_matrix_UB_33      0.0033003000
_diffrn_radiation_collimation    0.3
_diffrn_radiation_monochromator  'Confocal mirrors, Varimax'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0482
_diffrn_reflns_av_unetI/netI     0.0189
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       38
_diffrn_reflns_limit_l_min       -38
_diffrn_reflns_number            58425
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         70.337
_diffrn_reflns_theta_min         2.030
_diffrn_source                   'Rotating Anode'
_diffrn_source_current           30.0
_diffrn_source_power             1.2
_diffrn_source_target            Cu
_diffrn_source_type              'Rotating Anode'
_diffrn_source_voltage           40.0
_exptl_absorpt_coefficient_mu    0.684
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.93804
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'CrysAlisPro 1.171.38.41 (Rigaku Oxford Diffraction, 2015) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.'
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.293
_exptl_crystal_description       plate
_exptl_crystal_F_000             1248
_exptl_crystal_recrystallization_method
'The material was recrystallised from ethanol by slow evaporation'
_exptl_crystal_size_max          0.29
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.450
_refine_diff_density_min         -0.205
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.030
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     413
_refine_ls_number_reflns         5761
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.030
_refine_ls_R_factor_all          0.0537
_refine_ls_R_factor_gt           0.0454
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0568P)^2^+1.5446P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1150
_refine_ls_wR_factor_ref         0.1211
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4923
_reflns_number_total             5761
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d1cc02097h2.cif
_cod_data_source_block           2016sot0060_d1_100k
_cod_depositor_comments
'Adding full bibliography for 7128287--7128289.cif.'
_cod_database_code               7128287
_diffrn_measurement_device_type2 'Rigaku AFC11'
_reflns_odcompleteness_completeness 99.51
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     70.20
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
2.a Secondary CH2 refined with riding coordinates:
 C107(H10C,H10D), C112(H11A,H11B), C207(H20C,H20D), C212(H21A,H21B)
2.b Aromatic/amide H refined with riding coordinates:
 C101(H10A), C102(H10B), C103(H103), C104(H104), C105(H105), C108(H108),
 C109(H109), C114(H114), C115(H115), C116(H116), C117(H117), C118(H118),
 C201(H20A), C202(H20B), C203(H203), C204(H204), C205(H205), C208(H208),
 C209(H209), C214(H214), C215(H215), C216(H216), C217(H217), C218(H218)
;
_shelx_shelxl_version_number     2014/7
_olex2_date_sample_submission    2016-08-12
_olex2_diffrn_ambient_temperature_device 'Oxford Cryosystems'
_olex2_exptl_crystal_mounting_method
'The crystal was mounted on a MITIGEN holder with silicon oil'
_olex2_submission_original_sample_id 'DCW/7964/218.3 '
_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
- Detector area scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.515
_oxdiff_exptl_absorpt_empirical_full_min 0.437