A direct entry to polycyclic quinoxaline derivatives <i>via</i> I<sub>2</sub>-DMSO mediated oxidative decarboxylation of α-amino acids and the subsequent Pictet-Spengler cyclization reaction.
Samanta, Surya Kanta; Sarkar, Rumpa; Sengupta, Utsav; Das, Sayan; Ganguly, Debabani; Hasija, Avantika; Chopra, Deepak; Bera, Mrinal K.; Organic & biomolecular chemistry 20 (2022) 4650–4658; doi:10.1039/d2ob00503d

data_7158698
_publ_section_title
;
 A direct entry to polycyclic quinoxaline derivatives <i>via</i>
 I<sub>2</sub>-DMSO mediated oxidative decarboxylation of \a-amino acids
 and the subsequent Pictet-Spengler cyclization reaction.
;
_journal_issue                   22
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              4650
_journal_page_last               4658
_journal_paper_doi               10.1039/d2ob00503d
_journal_volume                  20
_journal_year                    2022
_chemical_formula_moiety         'C22 H14 N2 O'
_chemical_formula_sum            'C22 H14 N2 O'
_chemical_formula_weight         322.35
_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
_audit_creation_date             2020-03-06
_audit_creation_method
;
Olex2 1.3
(compiled Nov 21 2019 18:26:39 for OlexSys, GUI svn.r6003)
;
_audit_update_record
;
2020-12-07 deposited with the CCDC.	2022-05-16 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90.160(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   3.8833(4)
_cell_length_b                   16.3577(13)
_cell_length_c                   23.692(2)
_cell_measurement_reflns_used    9896
_cell_measurement_temperature    100.0
_cell_measurement_theta_max      26.72
_cell_measurement_theta_min      2.49
_cell_volume                     1505.0(2)
_computing_cell_refinement       'SAINT v8.37A (Bruker, 2015)'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'SAINT v8.37A (Bruker, 2015)'
_computing_molecular_graphics    'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.3 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100.0
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1738
_diffrn_reflns_av_unetI/netI     0.0860
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            38900
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.896
_diffrn_reflns_theta_min         2.490
_diffrn_source_current           1.0
_diffrn_source_power             0.05
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_T_max  0.7454
_exptl_absorpt_correction_T_min  0.6113
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/5 (Bruker,2014/5) was used for absorption correction.
wR2(int) was 0.1618 before and 0.1008 after correction.
The Ratio of minimum to maximum transmission is 0.8201.
The \l/2 correction factor is 0.00150.
;
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.423
_exptl_crystal_description       rod
_exptl_crystal_F_000             672
_exptl_crystal_size_max          0.804
_exptl_crystal_size_mid          0.159
_exptl_crystal_size_min          0.062
_refine_diff_density_max         0.255
_refine_diff_density_min         -0.341
_refine_diff_density_rms         0.067
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     226
_refine_ls_number_reflns         3205
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.1234
_refine_ls_R_factor_gt           0.0609
_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^)+(0.0379P)^2^+1.1992P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1041
_refine_ls_wR_factor_ref         0.1229
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2004
_reflns_number_total             3205
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d2ob00503d2.cif
_cod_data_source_block           mkb_xrd6
_cod_depositor_comments
'Adding full bibliography for 7158698--7158699.cif.'
_cod_database_code               7158698
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.995
_shelx_estimated_absorpt_t_min   0.932
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups
2.a Aromatic/amide H refined with riding coordinates:
 C5(H5), C19(H19), C10(H10), C21(H21), C18(H18), C20(H20), C15(H15), C1(H1),
 C3(H3), C2(H2), C12(H12), C4(H4), C14(H14), C13(H13)
;
_shelx_res_checksum              12767
_olex2_submission_special_instructions 'No special instructions were received'