Exocyclic N-Acyliminium Ion (NAI) Cyclization: Access to Fully Substituted Oxazoles and Furocoumarins.
Babu, Venkata Nagarjuna; Murugan, Arumugavel; Katta, Narenderreddy; Devatha, Suman; Sharada, Duddu S.; The Journal of organic chemistry 84 (2019) 6631–6641; doi:10.1021/acs.joc.9b00096

data_4034632
_publ_section_title
;
 Exocyclic N-Acyliminium Ion (NAI) Cyclization: Access to Fully
 Substituted Oxazoles and Furocoumarins.
;
_journal_issue                   11
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              6631
_journal_page_last               6641
_journal_paper_doi               10.1021/acs.joc.9b00096
_journal_volume                  84
_journal_year                    2019
_chemical_formula_moiety         'C16 H17 Br N2 O4'
_chemical_formula_sum            'C16 H17 Br N2 O4'
_chemical_formula_weight         381.23
_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     direct
_atom_sites_solution_secondary   difmap
_audit_creation_date             2018-04-06
_audit_creation_method
;
  Olex2 1.1
  (compiled 2011.11.01 svn.r2039, GUI svn.r3906)
;
_cell_angle_alpha                79.346(9)
_cell_angle_beta                 72.139(10)
_cell_angle_gamma                65.185(11)
_cell_formula_units_Z            2
_cell_length_a                   9.1144(10)
_cell_length_b                   9.4623(10)
_cell_length_c                   10.9816(12)
_cell_measurement_reflns_used    1814
_cell_measurement_temperature    293
_cell_measurement_theta_max      71.0122
_cell_measurement_theta_min      4.2352
_cell_volume                     816.48(17)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
;
_computing_molecular_graphics
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_publication_material
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_structure_refinement
;
SHELXL, G.M. Sheldrick, Acta Cryst.
2008). A64, 112-122
;
_computing_structure_solution
;
SHELXS, G.M. Sheldrick, Acta Cryst.
(2008). A64, 112-122
;
_diffrn_ambient_temperature      293
_diffrn_detector_area_resol_mean 16.1293
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 0.955
_diffrn_measurement_details
;
  1 omega  -67.00  -34.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      -33.5000  -57.0000  -60.0000 33

  2 omega  -49.00   37.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      -33.5000   38.0000   90.0000 86

  3 omega -101.00  -76.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      -33.5000  -57.0000 -120.0000 25

  4 omega -102.00  -69.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      -33.5000  178.0000 -180.0000 33

  5 omega  -98.00  -72.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      -33.5000  -57.0000  -60.0000 26

  6 omega   35.00   98.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000   57.0000  -90.0000 63

  7 omega    5.00   33.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000  -77.0000  150.0000 28

  8 omega   43.00  115.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000   57.0000  120.0000 72

  9 omega   38.00  108.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000 -125.0000  120.0000 70

 10 omega   38.00  121.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000   57.0000    0.0000 83

 11 omega   38.00   74.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -       54.0000  -77.0000  150.0000 36

 12 omega   59.00  112.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000 -111.0000 -180.0000 53

 13 omega   59.00   85.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -50.0000  -60.0000 26

 14 omega   78.00  178.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000   25.0000 -150.0000 100

 15 omega   39.00   93.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -38.0000 -180.0000 54

 16 omega   83.00  172.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000   25.0000  120.0000 89

 17 omega   43.00   93.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -38.0000   60.0000 50

 18 omega   83.00  114.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000 -111.0000   30.0000 31

 19 omega   46.00   99.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -63.0000   30.0000 53

 20 omega  106.00  141.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  178.0000    0.0000 35

 21 omega   66.00   91.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  178.0000    0.0000 25

 22 omega  109.00  176.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  111.0000  120.0000 67

 23 omega   39.00   87.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -38.0000 -120.0000 48

 24 omega   39.00   64.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -77.0000   30.0000 25

 25 omega   39.00  107.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000 -111.0000  -30.0000 68

 26 omega   56.00   85.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -25.0000  -60.0000 29

 27 omega   47.00  103.00   1.0000    1.5000
omega____ theta____ kappa____ phi______ frames
    -      108.0000  -50.0000  120.0000 56
;
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_UB_11      -0.1161537000
_diffrn_orient_matrix_UB_12      -0.0470399000
_diffrn_orient_matrix_UB_13      0.1197489000
_diffrn_orient_matrix_UB_21      -0.1535411000
_diffrn_orient_matrix_UB_22      0.1166319000
_diffrn_orient_matrix_UB_23      -0.0466598000
_diffrn_orient_matrix_UB_31      0.0077577000
_diffrn_orient_matrix_UB_32      -0.1284344000
_diffrn_orient_matrix_UB_33      -0.0727932000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.0303
_diffrn_reflns_av_unetI/netI     0.0465
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            5203
_diffrn_reflns_theta_full        71.15
_diffrn_reflns_theta_max         71.15
_diffrn_reflns_theta_min         4.24
_diffrn_source                   'SuperNova (Cu) X-ray Source'
_diffrn_source_current           n/a
_diffrn_source_voltage           n/a
_exptl_absorpt_coefficient_mu    3.628
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.87230
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.35.19 (release 27-10-2011 CrysAlis171 .NET)
(compiled Oct 27 2011,15:02:11)
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    1.551
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             388
_exptl_crystal_size_max          0.08
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.464
_refine_diff_density_min         -0.620
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.179
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     210
_refine_ls_number_reflns         3025
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.179
_refine_ls_R_factor_all          0.0626
_refine_ls_R_factor_gt           0.0453
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.7415P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1389
_refine_ls_wR_factor_ref         0.1473
_reflns_number_gt                2305
_reflns_number_total             3025
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo9b00096_si_002.cif
_cod_data_source_block           exp_5510
_cod_original_cell_volume        816.48(16)
_cod_database_code               4034632
_chemical_oxdiff_formula         'C16 H17 O4 Br N2'
_reflns_odcompleteness_completeness 98.90
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     66.97