Synthesis of <i>gem</i>-dibromo 1,3-oxazines by NBS-mediated electrophilic cyclization of propargylic amides.
Zhang, Huaxin; Xiong, Yongge; Bai, Jiang; Yang, Ruchun; Song, Xian-Rong; Xiao, Qiang; Organic & biomolecular chemistry 21 (2023) 4578–4582; doi:10.1039/d3ob00623a

data_7159347
_publ_section_title
;
 Synthesis of <i>gem</i>-dibromo 1,3-oxazines by NBS-mediated
 electrophilic cyclization of propargylic amides.
;
_journal_issue                   22
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              4578
_journal_page_last               4582
_journal_paper_doi               10.1039/d3ob00623a
_journal_volume                  21
_journal_year                    2023
_chemical_absolute_configuration rm
_chemical_formula_sum            'C18 H17 Br2 N O2'
_chemical_formula_weight         439.15
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2023-04-20 deposited with the CCDC.	2023-05-12 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.4782(13)
_cell_length_b                   14.044(2)
_cell_length_c                   14.818(2)
_cell_measurement_reflns_used    3016
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      22.37
_cell_measurement_theta_min      2.77
_cell_volume                     1764.3(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0367
_diffrn_reflns_av_unetI/netI     0.0477
_diffrn_reflns_Laue_measured_fraction_full 0.994
_diffrn_reflns_Laue_measured_fraction_max 0.994
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            9012
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        24.995
_diffrn_reflns_theta_max         24.995
_diffrn_reflns_theta_min         2.768
_exptl_absorpt_coefficient_mu    4.603
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            COLORLESS
_exptl_crystal_density_diffrn    1.653
_exptl_crystal_description       BLOCK
_exptl_crystal_F_000             872
_exptl_crystal_size_max          0.260
_exptl_crystal_size_mid          0.240
_exptl_crystal_size_min          0.220
_refine_diff_density_max         0.250
_refine_diff_density_min         -0.459
_refine_diff_density_rms         0.060
_refine_ls_abs_structure_details
; 
 Flack x determined using 956 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.005(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.919
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         3085
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.919
_refine_ls_R_factor_all          0.0424
_refine_ls_R_factor_gt           0.0302
_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^)+(0.0337P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0599
_refine_ls_wR_factor_ref         0.0629
_reflns_Friedel_coverage         0.732
_reflns_Friedel_fraction_full    0.996
_reflns_Friedel_fraction_max     0.996
_reflns_number_gt                2597
_reflns_number_total             3085
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3ob00623a2.cif
_cod_data_source_block           1
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_chemical_absolute_configuration' value 'RM' was changed
to 'rm' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 8170 2020-07-09 18:12:32Z antanas 

 Adding full bibliography for 7159347.cif.
;
_cod_original_cell_volume        1764.3(5)
_cod_database_code               7159347
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.381
_shelx_estimated_absorpt_t_max   0.431
_shelx_res_checksum              7788
_shelx_hkl_checksum              1626