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_1548939
_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      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 100.094(5)
_cell_angle_gamma                90
_cell_formula_units_Z            2
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_cell_length_b                   7.0464(6)
_cell_length_c                   13.4791(10)
_cell_measurement_reflns_used    3951
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      71.976
_cell_measurement_theta_min      3.331
_cell_volume                     979.92(13)
_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_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II'
_diffrn_radiation_monochromator  'MONTEL Multi-layer'
_diffrn_radiation_source         'Incoatec micro-focus'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0979
_diffrn_reflns_av_unetI/netI     0.0572
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            21771
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         72.241
_diffrn_reflns_theta_min         3.330
_exptl_absorpt_coefficient_mu    1.173
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Krause et al. 2015)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.235
_exptl_crystal_description       block
_exptl_crystal_F_000             390
_exptl_crystal_size_max          0.198
_exptl_crystal_size_mid          0.175
_exptl_crystal_size_min          0.118
_exptl_transmission_factor_max   0.8940
_exptl_transmission_factor_min   0.7921
_refine_diff_density_max         0.231
_refine_diff_density_min         -0.514
_refine_diff_density_rms         0.064
_refine_ls_abs_structure_details
;
 Flack x determined using 1249 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.01(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.269
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
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_refine_ls_number_reflns         3869
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_refine_ls_restrained_S_all      1.269
_refine_ls_R_factor_all          0.0774
_refine_ls_R_factor_gt           0.0596
_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^)+(0.1164P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1657
_refine_ls_wR_factor_ref         0.2024
_reflns_Friedel_coverage         0.841
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.996
_reflns_number_gt                3398
_reflns_number_total             3869
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8sc00020d2.cif
_cod_data_source_block           kr565-a
_cod_depositor_comments
'Adding full bibliography for 1548939--1548940.cif.'
_cod_database_code               1548939
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.801
_shelx_estimated_absorpt_t_max   0.874
_shelx_res_checksum              89811