Acyl polysilanes: new acyl anion equivalents for additions to electron-deficient alkenes.
Bower, Justin; Box, Matthew R.; Czyzewski, Michal; Goeta, Andres E.; Steel, Patrick G.; Organic letters 11 (2009) 2744–2747; doi:10.1021/ol900813z

data_1503961
_publ_section_title
;
 Acyl polysilanes: new acyl anion equivalents for additions to
 electron-deficient alkenes.
;
_journal_issue                   13
_journal_name_full               'Organic letters'
_journal_page_first              2744
_journal_page_last               2747
_journal_paper_doi               10.1021/ol900813z
_journal_volume                  11
_journal_year                    2009
_chemical_formula_sum            'C24 H50 O5 Si4'
_chemical_formula_weight         531.00
_chemical_name_systematic
;
<i>(E)</i>
Ethyl-3-(2'-tertbutyl-3'-ethoxycarbonyl-2'-(1",1"-bistrimethylsilyl-2",2",2"-
trimethyldisilanyl)cyclop-1'-yl)-prop-2-enoate
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 128.4340(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   25.1341(12)
_cell_length_b                   9.5269(5)
_cell_length_c                   16.8986(8)
_cell_measurement_reflns_used    6385
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      30.24
_cell_measurement_theta_min      2.45
_cell_volume                     3169.6(3)
_computing_cell_refinement       'SMART V5.629 (Bruker, 2003a)'
_computing_data_collection       'SMART V5.629 (Bruker, 2003a)'
_computing_data_reduction        'SAINT V6.45A (Bruker, 2003b)'
_computing_molecular_graphics    'SHELXTL V6.14 (Bruker, 2003c)'
_computing_publication_material  'publCIF V1.9.0_c (Westrip, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 0.962
_diffrn_measured_fraction_theta_max 0.860
_diffrn_measurement_device_type  'Bruker SMART-1K CCD Diffractometer'
_diffrn_measurement_method       \w
_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  0.0326
_diffrn_reflns_av_sigmaI/netI    0.0564
_diffrn_reflns_limit_h_max       35
_diffrn_reflns_limit_h_min       -35
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            8871
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         30.47
_diffrn_reflns_theta_min         1.54
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.216
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.113
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular block'
_exptl_crystal_F_000             1160
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.470
_refine_diff_density_min         -0.480
_refine_diff_density_rms         0.095
_refine_ls_abs_structure_details 'Flack (1983), 979 Friedel pairs'
_refine_ls_abs_structure_Flack   0.63(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     313
_refine_ls_number_reflns         5357
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0556
_refine_ls_R_factor_gt           0.0520
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1231P)^2^+0.2508P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1593
_refine_ls_wR_factor_ref         0.1635
_reflns_number_gt                5031
_reflns_number_total             5357
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol900813z_si_001.cif
_cod_data_source_block           07srv062
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               1503961