Regio- and Stereoselective Enolizations Using Calcium Bis(hexamethyldisilazide) as a Base: Synthetic, Solid-State, and Solution Studies
He, Xuyang; Hurley, Erin; Noll, Bruce C.; Henderson, Kenneth W.; Organometallics 27 (2008) 3094–; doi:10.1021/om7011908

data_4070991
_publ_section_title
;
 Regio- and Stereoselective Enolizations Using Calcium
 Bis(hexamethyldisilazide) as a Base: Synthetic, Solid-State, and Solution
 Studies
;
_journal_issue                   13
_journal_name_full               Organometallics
_journal_page_first              3094
_journal_paper_doi               10.1021/om7011908
_journal_volume                  27
_journal_year                    2008
_chemical_compound_source        synthesized
_chemical_formula_moiety         'C39 H75 Ca2 O9, C18 H54 Ca1 N3 Si6'
_chemical_formula_sum            'C57 H129 Ca3 N3 O9 Si6'
_chemical_formula_weight         1289.41
_space_group_IT_number           146
_symmetry_cell_setting           hexagonal
_symmetry_Int_Tables_number      146
_symmetry_space_group_name_Hall  'R 3'
_symmetry_space_group_name_H-M   'R 3 :H'
_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                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   17.82680(10)
_cell_length_b                   17.82680(10)
_cell_length_c                   20.7329(2)
_cell_measurement_reflns_used    7289
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      35.97
_cell_measurement_theta_min      2.28
_cell_volume                     5706.07(7)
_computing_cell_refinement       'APEX2/SAINT (Bruker, 2004)'
_computing_data_collection       'APEX2 (Bruker, 2004)'
_computing_data_reduction        'SAINT/XPREP (Bruker, 2004; Sheldrick, 2003)'
_computing_molecular_graphics    'XP (Sheldrick, 1998)'
_computing_publication_material  'XCIF (Sheldrick, 2001)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker SMART APEX CCD area detector'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0348
_diffrn_reflns_av_sigmaI/netI    0.0284
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       -29
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            62830
_diffrn_reflns_theta_full        36.30
_diffrn_reflns_theta_max         36.30
_diffrn_reflns_theta_min         1.64
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Siemens KFFMO2K-90'
_exptl_absorpt_coefficient_mu    0.358
_exptl_absorpt_correction_T_max  0.96
_exptl_absorpt_correction_T_min  0.90
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'Blessing, R. H. (1995) Acta Cryst. A51, 33-38.'
_exptl_crystal_colour            'clear colourless'
_exptl_crystal_density_diffrn    1.126
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             2124
_exptl_crystal_recrystallization_method
'recrystallized on standing from thf solution'
_exptl_crystal_size_max          0.29
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.558
_refine_diff_density_min         -0.247
_refine_diff_density_rms         0.047
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.016(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.042
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     244
_refine_ls_number_reflns         12061
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0345
_refine_ls_R_factor_gt           0.0295
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0381P)^2^+1.0486P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0686
_refine_ls_wR_factor_ref         0.0712
_reflns_number_gt                11097
_reflns_number_total             12061
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om7011908-file001.cif
_cod_data_source_block           compound16
_cod_original_sg_symbol_H-M      'R 3'
_cod_database_code               4070991