Kinetics and Mechanism of Ketone Enolization Mediated by Magnesium Bis(hexamethyldisilazide)
Xuyang He; J. Jacob Morris; Bruce C. Noll; Seth N. Brown; Kenneth W. Henderson; Journal of the American Chemical Society 128 (2006) 13599–13610; doi:10.1021/ja064927w

data_4110975
_publ_contact_author_address
;University of Notre Dame
Department of Chemistry
Notre Dame, IN 46556-5670
;
_publ_contact_author_email       khenders@nd.edu
_publ_contact_author_fax         574.631.6652
_publ_contact_author_name        'Kenneth W. Henderson'
_publ_contact_author_phone       574.631.8025
_publ_section_title
;
 Kinetics and Mechanism of Ketone Enolization Mediated by Magnesium
 Bis(hexamethyldisilazide)
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13599
_journal_page_last               13610
_journal_paper_doi               10.1021/ja064927w
_journal_volume                  128
_journal_year                    2006
_chemical_compound_source        synthesized
_chemical_formula_moiety         'C21 H54 Mg N2 O Si4'
_chemical_formula_sum            'C21 H54 Mg N2 O Si4'
_chemical_formula_weight         487.33
_chemical_name_common            'Mg(HMDS)~2~ Pivalone'
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      15
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 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                 93.029(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   21.135(3)
_cell_length_b                   8.3722(10)
_cell_length_c                   37.287(5)
_cell_measurement_reflns_used    7137
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.8442
_cell_measurement_theta_min      2.4665
_cell_volume                     6588.6(15)
_computing_cell_refinement       'APEX2/SAINT (Bruker, 2004)'
_computing_data_collection       'SMART (Bruker, 2001)'
_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 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker SMART Apex CCD diffractometer'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0254
_diffrn_reflns_av_sigmaI/netI    0.0264
_diffrn_reflns_limit_h_max       28
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       50
_diffrn_reflns_limit_l_min       -46
_diffrn_reflns_number            27124
_diffrn_reflns_theta_full        28.88
_diffrn_reflns_theta_max         28.88
_diffrn_reflns_theta_min         1.93
_diffrn_source_type              'Siemens KFFMO2K-90'
_exptl_absorpt_coefficient_mu    0.213
_exptl_absorpt_correction_T_max  0.94
_exptl_absorpt_correction_T_min  0.91
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    0.983
_exptl_crystal_description       plate
_exptl_crystal_F_000             2160
_exptl_crystal_recrystallization_method
'crystallized on cooling in hexane solution from 20 \%C to 5 \%C.'
_exptl_crystal_size_max          0.49
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.28
_refine_diff_density_max         0.427
_refine_diff_density_min         -0.419
_refine_diff_density_rms         0.074
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.291
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     304
_refine_ls_number_reflns         8604
_refine_ls_number_restraints     12
_refine_ls_restrained_S_all      1.294
_refine_ls_R_factor_all          0.0908
_refine_ls_R_factor_gt           0.0851
_refine_ls_shift/su_max          0.010
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0611P)^2^+12.6306P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1990
_refine_ls_wR_factor_ref         0.2021
_reflns_number_gt                7945
_reflns_number_total             8604
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja064927wsi20060711_044458.cif
_cod_data_source_block           cmpd3
_cod_original_cell_volume        6588.4(14)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4110975