N-silyl oxyketene imines are underused yet highly versatile reagents for catalytic asymmetric synthesis.
Denmark, Scott E.; Wilson, Tyler W.; Nature chemistry 2 (2010) 937–943; doi:10.1038/nchem.857

data_1508140
_publ_contact_author
; 
Danielle L. Gray 
University of Illinois 
School of Chemical Sciences, Box 59-1 
505 South Mathews Avenue 
Urbana, Illinois  61801 
USA 
;
_publ_section_title
;
 N-silyl oxyketene imines are underused yet highly versatile reagents for
 catalytic asymmetric synthesis.
;
_journal_issue                   11
_journal_name_full               'Nature chemistry'
_journal_page_first              937
_journal_page_last               943
_journal_paper_doi               10.1038/nchem.857
_journal_volume                  2
_journal_year                    2010
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C17 H25 N O2'
_chemical_formula_sum            'C17 H25 N O2'
_chemical_formula_weight         275.38
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
; 
? 
;
_cell_angle_alpha                90.00
_cell_angle_beta                 94.388(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.2338(7)
_cell_length_b                   6.6050(5)
_cell_length_c                   11.9985(8)
_cell_measurement_reflns_used    4407
_cell_measurement_temperature    198(2)
_cell_measurement_theta_max      64.44
_cell_measurement_theta_min      3.69
_cell_volume                     808.65(10)
_computing_cell_refinement       'SAINT V7.23A (Bruker, 2005)'
_computing_data_collection       'APEX2 V2.0-1 (Bruker, 2004)'
_computing_data_reduction
; 
SAINT V7.23A, XPREP V2005/2, SADABS V2007/4, TWINABS V2007/5 
(Bruker, 2005 & 2007) 
;
_computing_molecular_graphics
; 
SHELXTL V6.12 (Bruker, 2005), CrystalMaker v2.1.3 (CrystalMaker, 1994) 
;
_computing_publication_material  'XCIF V6.12 (Bruker, 2005)'
_computing_structure_refinement  'SHELXTL V6.12 (Bruker, 2005)'
_computing_structure_solution    'SHELXTL V6.12 (Bruker, 2005)'
_diffrn_ambient_temperature      198(2)
_diffrn_measured_fraction_theta_full 0.962
_diffrn_measured_fraction_theta_max 0.962
_diffrn_measurement_device       'Bruker Kappa/ApexII CCD'
_diffrn_measurement_method       'profile data from \f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_radiation_wavelength_id  b40has
_diffrn_reflns_av_R_equivalents  0.0158
_diffrn_reflns_av_sigmaI/netI    0.0176
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            5440
_diffrn_reflns_theta_full        64.86
_diffrn_reflns_theta_max         64.86
_diffrn_reflns_theta_min         3.69
_exptl_absorpt_coefficient_mu    0.575
_exptl_absorpt_correction_T_max  0.9426
_exptl_absorpt_correction_T_min  0.8845
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details   'SHELXTL/XPREP V2005/2 (Bruker, 2005)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.131
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             300
_exptl_crystal_id                b40has
_exptl_crystal_preparation
; 
The data crystal was mounted using oil (Parantone-N, Exxon) to a 
0.3 mm cryo-loop (Hampton Research). 
;
_exptl_crystal_size_max          0.558
_exptl_crystal_size_mid          0.161
_exptl_crystal_size_min          0.154
_refine_diff_density_max         0.098
_refine_diff_density_min         -0.154
_refine_diff_density_rms         0.029
_refine_ls_abs_structure_details
;
In order to be able to confirm the absolute structure of the molecule, data was 
collected using Cu radiation.  On the basis of 975 unmerged 
Friedel opposites, the Flack parameter was determined to be unreliable 
(Flack, 1983 & 2000).  The absolute structure was confirmed using Bayesian 
statistics on 953 select Bijvoet pairs (Hooft, Straver & Spek, 2008).  The 
Hooft y parameter was determined to be 0.09(6).  This supports the given 
absolute structure configuration with negligible contribution from the racemate.
;
_refine_ls_abs_structure_Flack   0.09(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.083
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     189
_refine_ls_number_reflns         2420
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.083
_refine_ls_R_factor_all          0.0266
_refine_ls_R_factor_gt           0.0263
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0323P)^2^+0.1171P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0656
_refine_ls_wR_factor_ref         0.0658
_reflns_number_gt                2391
_reflns_number_total             2420
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            nchem.857-s2.cif
_cod_data_source_block           b40has
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      'P2(1)   '
_cod_database_code               1508140
_refine_ls_abs_structure_hooft   0.09(6)