Lewis acid-promoted [2 + 2] cycloadditions of alkenes with aryl ketenes.
Rigsbee, E. M.; Zhou, C.; Rasik, C. M.; Spitz, A. Z.; Nichols, A. J.; Brown, M. K.; Organic & biomolecular chemistry 14 (2016) 5477–5480; doi:10.1039/c5ob01837d

data_7154733
_publ_section_title
;
 Lewis acid-promoted [2 + 2] cycloadditions of alkenes with aryl ketenes.
;
_journal_issue                   24
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5477
_journal_page_last               5480
_journal_paper_doi               10.1039/c5ob01837d
_journal_volume                  14
_journal_year                    2016
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C20 H24 O1 Si1'
_chemical_formula_sum            'C20 H24 O Si'
_chemical_formula_weight         308.50
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     other
_audit_creation_date             2015-02-27
_audit_creation_method           CRYSTALS_ver_14.61
_audit_update_record
;
2015-09-01 deposited with the CCDC.
2015-09-22 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.2256(13)
_cell_length_b                   19.596(3)
_cell_length_c                   7.9601(12)
_cell_measurement_reflns_used    4997
_cell_measurement_temperature    150
_cell_measurement_theta_max      30
_cell_measurement_theta_min      3
_cell_volume                     1751.0(4)
_computing_cell_refinement       'Apex2 (Bruker AXS, 2006)'
_computing_data_collection       'Apex2 (Bruker AXS, 2006)'
_computing_data_reduction        'Apex2 (Bruker AXS, 2006)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'Superflip (Palatinus & Chapuis, 2007)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.979
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Bruker Kappa Apex2'
_diffrn_measurement_method       '\f & \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.028
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       6
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            7404
_diffrn_reflns_theta_full        28.036
_diffrn_reflns_theta_max         30.146
_diffrn_reflns_theta_min         2.091
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.134
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.98
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Siemens, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.170
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             664
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_min          0.050
_refine_diff_density_max         0.38
_refine_diff_density_min         -0.22
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0075
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         2704
_refine_ls_number_restraints     1
_refine_ls_R_factor_all          0.0418
_refine_ls_R_factor_gt           0.0354
_refine_ls_shift/su_max          0.0009545
_refine_ls_shift/su_mean         0.0000422
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method= Modified Sheldrick 
 w=1/[\s^2^(F^2^) + ( 0.05P)^2^ + 0.28P] 
 ,where P=(max(Fo^2^,0) + 2Fc^2^)/3 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0944
_refine_ls_wR_factor_gt          0.0871
_refine_ls_wR_factor_ref         0.0944
_reflns_limit_h_max              15
_reflns_limit_h_min              0
_reflns_limit_k_max              27
_reflns_limit_k_min              0
_reflns_limit_l_max              11
_reflns_limit_l_min              0
_reflns_number_gt                2357
_reflns_number_total             2711
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   0.00
_oxford_diffrn_Wilson_scale      0.00
_oxford_refine_ls_r_factor_ref   0.0418
_oxford_refine_ls_scale          0.21385(19)
_oxford_reflns_number_all        2704
_oxford_reflns_threshold_expression_ref I>-3.0\s(I)
_oxford_structure_analysis_title 'mo_15023_0ma in Pca2(1)'
_cod_data_source_file            c5ob01837d3.cif
_cod_data_source_block           15023
_cod_depositor_comments
;
The following automatic conversions were performed:

'_atom_sites_solution_primary' value 'Other' changed to 'other'
according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 3271 2015-04-21 07:52:19Z andrius 

 Adding full bibliography for 7154733.cif.
;
_cod_original_cell_volume        1751.1(3)
_cod_original_sg_symbol_H-M      'P c a 21 '
_cod_original_formula_sum        'C20 H24 O1 Si1'
_cod_database_code               7154733