Histidine-Catalyzed Asymmetric Aldol Addition of Enolizable Aldehydes: Insights into its Mechanism
Ulf Scheffler; Rainer Mahrwald; Journal of Organic Chemistry 77 (2012) 2310–2330; doi:10.1021/jo202558f

data_4027037
_publ_section_title
;
 Histidine-Catalyzed Asymmetric Aldol Addition of Enolizable Aldehydes:
 Insights into its Mechanism
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              2310
_journal_page_last               2330
_journal_paper_doi               10.1021/jo202558f
_journal_volume                  77
_journal_year                    2012
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C16 H30 O6 Si'
_chemical_formula_sum            'C16 H30 O6 Si'
_chemical_formula_weight         346.49
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3165(3)
_cell_length_b                   9.6178(3)
_cell_length_c                   26.2338(9)
_cell_measurement_reflns_used    15980
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      29.52
_cell_measurement_theta_min      2.63
_cell_volume                     1846.04(11)
_computing_cell_refinement       'X-AREA (Stoe & Cie, 2002)'
_computing_data_collection       'X-AREA (Stoe & Cie, 2002)'
_computing_data_reduction        'X-RED (Stoe & Cie, 2002)'
_computing_molecular_graphics    'PLATON, 1990'
_computing_publication_material  'PLATON, 1990'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 6.67
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device       'Stoe IPDS-2t diffractometer'
_diffrn_measurement_method       '\w-rotation,\w-incr.=1\%,319 exposures'
_diffrn_radiation_collimation    '0.5 mm diameter monocapillary'
_diffrn_radiation_monochromator  'planar graphite'
_diffrn_radiation_source         'long fine focus sealed x-ray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1021
_diffrn_reflns_av_sigmaI/netI    0.0682
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            13197
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         2.63
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.153
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.247
_exptl_crystal_description       fragment
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.36
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.365
_refine_diff_density_min         -0.351
_refine_diff_density_rms         0.115
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.08(13)
_refine_ls_extinction_coef       0.023(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.033
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         4205
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.0502
_refine_ls_R_factor_gt           0.0449
_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^)+(0.0724P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1103
_refine_ls_wR_factor_ref         0.1127
_reflns_number_gt                3813
_reflns_number_total             4205
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202558f_d39.cif
_cod_data_source_block           274cy
_cod_database_code               4027037