Synthesis of 1,2-diaminotruxinic δ-cyclobutanes by BF<sub>3</sub>-controlled [2 + 2]-photocycloaddition of 5(4<i>H</i>)-oxazolones and stereoselective expansion of δ-cyclobutanes to give highly substituted pyrrolidine-2,5-dicarboxylates.
Sierra, Sonia; López, Rosa; Gómez-Bengoa, Enrique; Falvello, Larry R.; Urriolabeitia, Esteban P.; Organic & biomolecular chemistry 21 (2023) 3203–3213; doi:10.1039/d3ob00284e

data_7159256
_publ_section_title
;
 Synthesis of 1,2-diaminotruxinic &#x3b4;-cyclobutanes by
 BF<sub>3</sub>-controlled [2 + 2]-photocycloaddition of
 5(4<i>H</i>)-oxazolones and stereoselective expansion of
 &#x3b4;-cyclobutanes to give highly substituted
 pyrrolidine-2,5-dicarboxylates.
;
_journal_issue                   15
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3203
_journal_page_last               3213
_journal_paper_doi               10.1039/d3ob00284e
_journal_volume                  21
_journal_year                    2023
_chemical_formula_moiety         'C34 H26 F4 N2 O6, C H Cl3'
_chemical_formula_sum            'C35 H27 Cl3 F4 N2 O6'
_chemical_formula_weight         753.93
_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   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   'Fourier Difference Synthesis'
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2022-06-06 deposited with the CCDC.	2023-03-22 downloaded from the CCDC.
;
_cell_angle_alpha                99.183(2)
_cell_angle_beta                 93.990(2)
_cell_angle_gamma                108.186(2)
_cell_formula_units_Z            2
_cell_length_a                   9.4722(13)
_cell_length_b                   10.4254(15)
_cell_length_c                   18.483(3)
_cell_measurement_reflns_used    3825
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      24.704
_cell_measurement_theta_min      2.180
_cell_volume                     1697.9(4)
_computing_cell_refinement       'SAINT+ in APEX3 v. 2017.3 (Bruker AXS, 2008)'
_computing_data_collection       'SMART in APEX2 v. 2008.4 (Bruker AXS, 2008)'
_computing_data_reduction        'SAINT+ in APEX3 v. 2017.3 (Bruker AXS, 2008)'
_computing_molecular_graphics    'ORTEP-3 (farrugia, 2012)'
_computing_publication_material  'XCIF program, PLATON(Spek, 1998)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXS-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 8.26
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX DUO system'
_diffrn_measurement_method       'narrow \w frames'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0377
_diffrn_reflns_av_unetI/netI     0.0537
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            17823
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.401
_diffrn_reflns_theta_min         1.125
_exptl_absorpt_coefficient_mu    0.341
_exptl_absorpt_correction_T_max  0.9583
_exptl_absorpt_correction_T_min  0.8372
_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            colourless
_exptl_crystal_density_diffrn    1.475
_exptl_crystal_description       plate
_exptl_crystal_F_000             772
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.170
_exptl_crystal_size_min          0.115
_refine_diff_density_max         0.495
_refine_diff_density_min         -0.468
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.011
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     576
_refine_ls_number_reflns         6931
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      447.202
_refine_ls_R_factor_all          0.0825
_refine_ls_R_factor_gt           0.0453
_refine_ls_shift/su_max          0.028
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0495P)^2^+0.5915P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1005
_refine_ls_wR_factor_ref         0.1160
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4584
_reflns_number_total             6931
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d3ob00284e2.cif
_cod_data_source_block           cmpnd_2s
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_atom_sites_solution_primary' value 'Direct method' was
changed to 'direct'.

Automatic conversion script
Id: cif_fix_values 7556 2019-12-06 15:28:31Z antanas 

 Adding full bibliography for 7159254--7159256.cif.
;
_cod_database_code               7159256
_shelx_shelxl_version_number     2018/3
_shelx_res_checksum              4472
_shelx_hkl_checksum              66719