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_4027035
_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 rm
_chemical_formula_sum            'C10 H18 O4'
_chemical_formula_weight         202.24
_chemical_name_systematic
; 
 (S)-3-((R)-2,2-Dimethyl-1,3-dioxolan-4-yl)-3-hydroxy-2,2-dimethylpropanal 
;
_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                   6.6073(2)
_cell_length_b                   10.3686(4)
_cell_length_c                   15.9951(4)
_cell_measurement_reflns_used    21556
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.33
_cell_measurement_theta_min      2.34
_cell_volume                     1095.80(6)
_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 0.997
_diffrn_measured_fraction_theta_max 0.998
_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  0.0968
_diffrn_reflns_av_sigmaI/netI    0.0355
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            23683
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.55
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_T_max  0.9944
_exptl_absorpt_correction_T_min  0.9565
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'PLATON, 1990'
_exptl_crystal_colour            'light yellow'
_exptl_crystal_density_diffrn    1.226
_exptl_crystal_description       fragment
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.475
_refine_diff_density_min         -0.158
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.4(10)
_refine_ls_extinction_coef       0.029(5)
_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   1.069
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     136
_refine_ls_number_reflns         2149
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.069
_refine_ls_R_factor_all          0.0398
_refine_ls_R_factor_gt           0.0365
_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^)+(0.0586P)^2^+0.1208P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0937
_refine_ls_wR_factor_ref         0.0954
_reflns_number_gt                1997
_reflns_number_total             2149
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo202558f_anti13m.cif
_cod_data_source_block           256wg
_cod_database_code               4027035