Asymmetric synthesis of spirocyclic isobenzofuranones <i>via</i> a squaramide-catalysed sulfa-Michael desymmetrisation reaction.
Tamanna, ?; Sharma, Deepak; Chauhan, Pankaj; Organic & biomolecular chemistry 21 (2023) 2570–2574; doi:10.1039/d3ob00126a

data_7159194
_publ_section_title
;
 Asymmetric synthesis of spirocyclic isobenzofuranones <i>via</i> a
 squaramide-catalysed sulfa-Michael desymmetrisation reaction.
;
_journal_issue                   12
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              2570
_journal_page_last               2574
_journal_paper_doi               10.1039/d3ob00126a
_journal_volume                  21
_journal_year                    2023
_chemical_formula_sum            'C19 H13 Br O3 S'
_chemical_formula_weight         401.26
_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-2018/3
_audit_update_record
;
2022-11-23 deposited with the CCDC.	2023-02-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.6268(5)
_cell_length_b                   9.3115(7)
_cell_length_c                   24.2573(18)
_cell_measurement_temperature    100(2)
_cell_volume                     1722.7(2)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0511
_diffrn_reflns_av_unetI/netI     0.0335
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            15973
_diffrn_reflns_point_group_measured_fraction_full 0.993
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        66.504
_diffrn_reflns_theta_max         66.504
_diffrn_reflns_theta_min         3.644
_exptl_absorpt_coefficient_mu    4.504
_exptl_crystal_density_diffrn    1.547
_exptl_crystal_F_000             808
_refine_diff_density_max         0.614
_refine_diff_density_min         -0.383
_refine_diff_density_rms         0.057
_refine_ls_abs_structure_details
;
 Flack x determined using 1200 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.139(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.076
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         3008
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.076
_refine_ls_R_factor_all          0.0261
_refine_ls_R_factor_gt           0.0252
_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^)+(0.0293P)^2^+0.8608P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0632
_refine_ls_wR_factor_ref         0.0641
_reflns_Friedel_coverage         0.700
_reflns_Friedel_fraction_full    0.983
_reflns_Friedel_fraction_max     0.983
_reflns_number_gt                2940
_reflns_number_total             3008
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3ob00126a2.cif
_cod_data_source_block           cu_tc_673_0m_a
_cod_depositor_comments          'Adding full bibliography for 7159194.cif.'
_cod_database_code               7159194
_shelx_shelxl_version_number     2018/3
_shelx_res_checksum              25400