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_4070993
_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         'C66 H126 Ca4 N2 O6 Si4'
_chemical_formula_sum            'C66 H126 Ca4 N2 O6 Si4'
_chemical_formula_weight         1316.37
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 90.3790(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   14.9414(3)
_cell_length_b                   13.7179(3)
_cell_length_c                   18.2401(3)
_cell_measurement_reflns_used    9534
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.1874
_cell_measurement_theta_min      2.2998
_cell_volume                     3738.49(13)
_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)/enCIFer (CCDC, 2004)'
_computing_structure_refinement  'XL (Sheldrick, 2001)'
_computing_structure_solution    'XS (Sheldrick, 2001)'
_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 X8-ApexII CCD diffractometer'
_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  0.0373
_diffrn_reflns_av_sigmaI/netI    0.0259
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            63439
_diffrn_reflns_theta_full        27.88
_diffrn_reflns_theta_max         27.88
_diffrn_reflns_theta_min         1.76
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Siemens KFFMO2K-90'
_exptl_absorpt_coefficient_mu    0.400
_exptl_absorpt_correction_T_max  0.9783
_exptl_absorpt_correction_T_min  0.9011
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Sheldrick, G. M. (2004). SADABS. University of G\"ottingen, Germany.
;
_exptl_crystal_colour            'clear colorless'
_exptl_crystal_density_diffrn    1.169
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       hexagonal
_exptl_crystal_F_000             1440
_exptl_crystal_size_max          0.27
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.736
_refine_diff_density_min         -0.251
_refine_diff_density_rms         0.051
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     379
_refine_ls_number_reflns         8907
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0457
_refine_ls_R_factor_gt           0.0311
_refine_ls_shift/su_max          0.006
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0362P)^2^+1.7776P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0726
_refine_ls_wR_factor_ref         0.0802
_reflns_number_gt                7239
_reflns_number_total             8907
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om7011908-file001.cif
_cod_data_source_block           compound18
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4070993