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_4027027
_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 syn
_chemical_formula_moiety         'C11 H20 O4'
_chemical_formula_sum            'C11 H20 O4'
_chemical_formula_weight         216.27
_chemical_name_systematic
; 
 (S)-3-Hydroxy-2,2-dimethyl-3-((4R, 5S)-2,2,5-trimethyl-1,3-dioxolan-4-yl)
propanal
;
_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            8
_cell_length_a                   10.864(2)
_cell_length_b                   13.608(3)
_cell_length_c                   15.939(3)
_cell_measurement_reflns_used    1187
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.50
_cell_measurement_theta_min      2.65
_cell_volume                     2356.4(8)
_computing_cell_refinement       'STOE X-AREA'
_computing_data_collection       'STOE X-AREA'
_computing_data_reduction        XPREP
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'image plate (34 cm diameter)'
_diffrn_detector_area_resol_mean 6.67
_diffrn_detector_type            STOE
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_details      ' 360 frames, detector distance = 90 mm'
_diffrn_measurement_device       '2-circle goniometer'
_diffrn_measurement_device_type  'STOE IPDS 2T'
_diffrn_measurement_method       'rotation method'
_diffrn_radiation_collimation    '0.5 mm diameter, monocapillary'
_diffrn_radiation_monochromator  'plane graphite'
_diffrn_radiation_polarisn_norm  0
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0655
_diffrn_reflns_av_unetI/netI     0.0094
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            49995
_diffrn_reflns_theta_full        29.85
_diffrn_reflns_theta_max         29.85
_diffrn_reflns_theta_min         2.26
_diffrn_source
'sealed x-ray tube, 12 x 0.4 mm long-fine focus'
_diffrn_source_current           45
_diffrn_source_power             2.25
_diffrn_source_voltage           50
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.219
_exptl_crystal_description       block
_exptl_crystal_F_000             944
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.772
_refine_diff_density_min         -0.306
_refine_diff_density_rms         0.050
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.116
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     282
_refine_ls_number_reflns         3755
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.116
_refine_ls_R_factor_all          0.0374
_refine_ls_R_factor_gt           0.0357
_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^)+(0.0671P)^2^+0.3511P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0988
_refine_ls_wR_factor_ref         0.0998
_reflns_d_resolution_high        0.811
_reflns_d_resolution_low         9.004
_reflns_limit_h_max              15
_reflns_limit_h_min              0
_reflns_limit_k_max              19
_reflns_limit_k_min              0
_reflns_limit_l_max              22
_reflns_limit_l_min              0
_reflns_number_gt                3627
_reflns_number_total             3755
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202558f_13n.cif
_cod_data_source_block           c:xpm
_cod_database_code               4027027