Synthesis of 5<i>H</i>-chromeno[3,4-<i>b</i>]pyridines <i>via</i> DABCO-catalyzed [3 + 3] annulation of 3-nitro-2<i>H</i>-chromenes and allenoates.
Soares, Maria I. L.; Gomes, Clara S. B.; Oliveira, M Conceição; Marçalo, Joaquim; Pinho E Melo, Teresa M V D; Organic & biomolecular chemistry 19 (2021) 9711–9722; doi:10.1039/d1ob01130h

data_7158348
_publ_section_title
;
 Synthesis of 5<i>H</i>-chromeno[3,4-<i>b</i>]pyridines <i>via</i>
 DABCO-catalyzed [3 + 3] annulation of 3-nitro-2<i>H</i>-chromenes and
 allenoates.
;
_journal_issue                   44
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              9711
_journal_page_last               9722
_journal_paper_doi               10.1039/d1ob01130h
_journal_volume                  19
_journal_year                    2021
_chemical_formula_moiety         'C33 H29 N O7'
_chemical_formula_sum            'C33 H29 N O7'
_chemical_formula_weight         551.57
_chemical_name_systematic
'benzyl (E)-2-((4-(benzyloxy)-4-oxobut-2-en-2-yl)oxy)-7-ethoxy-5H-chromeno[3,4-b]pyridine-3-carboxylate'
_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
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2021-06-11 deposited with the CCDC.	2021-10-22 downloaded from the CCDC.
;
_cell_angle_alpha                101.823(13)
_cell_angle_beta                 109.747(10)
_cell_angle_gamma                91.715(13)
_cell_formula_units_Z            2
_cell_length_a                   10.646(2)
_cell_length_b                   11.634(3)
_cell_length_c                   12.087(3)
_cell_measurement_reflns_used    31917
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      25.681
_cell_measurement_theta_min      2.561
_cell_volume                     1371.1(6)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Ortep for Windows (Farrugia, 2012)'
_computing_publication_material  'WinGX publication routines (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'Bruker D8 VENTURE PHOTON 100 CMOS'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1499
_diffrn_reflns_av_unetI/netI     0.3266
_diffrn_reflns_Laue_measured_fraction_full 0.985
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            33320
_diffrn_reflns_point_group_measured_fraction_full 0.985
_diffrn_reflns_point_group_measured_fraction_max 0.982
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.357
_diffrn_reflns_theta_min         2.260
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_T_max  0.7463
_exptl_absorpt_correction_T_min  0.6106
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.336
_exptl_crystal_description       block
_exptl_crystal_F_000             580
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.120
_refine_diff_density_max         0.584
_refine_diff_density_min         -0.655
_refine_diff_density_rms         0.184
_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     366
_refine_ls_number_reflns         5500
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.1250
_refine_ls_R_factor_gt           0.0422
_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^)+(0.0457P)^2^+0.3809P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0985
_refine_ls_wR_factor_ref         0.1100
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4099
_reflns_number_total             5500
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d1ob01130h2.cif
_cod_data_source_block           3b
_cod_depositor_comments
'Adding full bibliography for 7158348--7158349.cif.'
_cod_original_cell_volume        1371.0(6)
_cod_database_code               7158348
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.981
_shelx_estimated_absorpt_t_max   0.989
_shelx_res_checksum              16348
_shelx_hkl_checksum              48582