An unusual stereoretentive 1,3-quaternary carbon shift resulting in an enantioselective Rh<sup>II</sup>-catalyzed formal [4+1]-cycloaddition between diazo compounds and vinyl ketenes.
Rodriguez, Kevin X.; Pilato, Tara C.; Ashfeld, Brandon L.; Chemical science 9 (2018) 3221–3226; doi:10.1039/c8sc00020d

data_1548940
_publ_section_title
;
 An unusual stereoretentive 1,3-quaternary carbon shift resulting in an
 enantioselective Rh<sup>II</sup>-catalyzed formal [4+1]-cycloaddition
 between diazo compounds and vinyl ketenes.
;
_journal_issue                   12
_journal_name_full               'Chemical science'
_journal_page_first              3221
_journal_page_last               3226
_journal_paper_doi               10.1039/c8sc00020d
_journal_volume                  9
_journal_year                    2018
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C22 H23 N O2 Si'
_chemical_formula_sum            'C22 H23 N O2 Si'
_chemical_formula_weight         361.50
_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'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     vecmap
_atom_sites_solution_secondary   difmap
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_audit_update_record
;
2017-06-20 deposited with the CCDC.
2018-02-19 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
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_cell_length_b                   11.6775(4)
_cell_length_c                   17.2070(6)
_cell_measurement_reflns_used    9670
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      71.652
_cell_measurement_theta_min      4.576
_cell_volume                     1892.08(11)
_computing_cell_refinement       'Bruker SAINT (Bruker, 2015)'
_computing_data_collection       'Bruker APEX-3 (Bruker, 2015)'
_computing_data_reduction        'Bruker SAINT (Bruker, 2015)'
_computing_molecular_graphics    'OLEX2 (Dolomanov et al., 2010)'
_computing_publication_material  'CIFTAB (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device_type  'Bruker APEX-II'
_diffrn_measurement_method       'combination of \w and \f-scans '
_diffrn_radiation_monochromator  'MONTEL Multi-layer'
_diffrn_radiation_source         'Incoatec micro-focus'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
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_diffrn_reflns_av_unetI/netI     0.0137
_diffrn_reflns_Laue_measured_fraction_full 0.985
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_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            40424
_diffrn_reflns_point_group_measured_fraction_full 0.987
_diffrn_reflns_point_group_measured_fraction_max 0.978
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         71.740
_diffrn_reflns_theta_min         4.576
_exptl_absorpt_coefficient_mu    1.214
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_exptl_absorpt_correction_T_min  0.6162
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Krause et al. 2015)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.269
_exptl_crystal_description       block
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.334
_exptl_crystal_size_mid          0.301
_exptl_crystal_size_min          0.222
_refine_diff_density_max         0.131
_refine_diff_density_min         -0.292
_refine_diff_density_rms         0.056
_refine_ls_abs_structure_details
;
 Flack x determined using 1553 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.048(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.103
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         3643
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.103
_refine_ls_R_factor_all          0.0266
_refine_ls_R_factor_gt           0.0266
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0404P)^2^+0.4173P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0703
_refine_ls_wR_factor_ref         0.0703
_reflns_Friedel_coverage         0.748
_reflns_Friedel_fraction_full    0.988
_reflns_Friedel_fraction_max     0.979
_reflns_number_gt                3638
_reflns_number_total             3643
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8sc00020d2.cif
_cod_data_source_block           KR41772
_cod_depositor_comments
'Adding full bibliography for 1548939--1548940.cif.'
_cod_database_code               1548940
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              34477