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_4027036
_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         'C17 H21 Br O4'
_chemical_formula_sum            'C17 H21 Br O4'
_chemical_formula_weight         369.25
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_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                   8.7936(7)
_cell_length_b                   8.8297(9)
_cell_length_c                   20.9298(10)
_cell_measurement_reflns_used    7438
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.49
_cell_measurement_theta_min      2.51
_cell_volume                     1625.1(2)
_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 0.990
_diffrn_measured_fraction_theta_max 0.992
_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  0.0940
_diffrn_reflns_av_sigmaI/netI    0.0553
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            14880
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         2.50
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.545
_exptl_absorpt_correction_T_max  0.6573
_exptl_absorpt_correction_T_min  0.5575
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'PLATON, 1990'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.509
_exptl_crystal_description       block
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.327
_refine_diff_density_min         -0.500
_refine_diff_density_rms         0.081
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.008(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.150
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     206
_refine_ls_number_reflns         3723
_refine_ls_number_restraints     54
_refine_ls_restrained_S_all      1.145
_refine_ls_R_factor_all          0.0451
_refine_ls_R_factor_gt           0.0404
_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^)+(0.0361P)^2^+1.3377P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0811
_refine_ls_wR_factor_ref         0.0924
_reflns_number_gt                3499
_reflns_number_total             3723
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202558f_d30.cif
_cod_data_source_block           58cyi
_cod_database_code               4027036